Background: Social capital is a set of shared values that allows individuals or groups receive emotional, instrumental or financial resources flow. In Ethiopia, despite people commonly involved in social networks, there is a dearth of evidence exploring whether membership in these networks enhances uptake of maternal and child health (MCH) services. Besides, little is known about approaches to effectively measure maternal social capital in the present study area in particular and in Ethiopia in general. Objective: The purpose of this study was to assess the influence of social capital on maternal and child health service utilization in Ethiopia with a special reference to south Gondar zone, northwest Ethiopia, 2022. Methods: Both qualitative and quantitative research methods were employed to address the objectives of the study. In the first study, we employed a qualitative study through key informant interviews and focus group discussions. A maximum variation purposive sampling technique was used to select 41 study participants (11 key informant interviews and 4 focus group discussions comprising 7-8 participants). To explore the role of social capital on MCH service use, postpartum mothers, community and religious leaders, women developmental army, and health extension workers were participated. Data were transcribed verbatim and thematic analyses were employed using ATLAS.ti software. The second paper was focused on development and validation of tool used for measuring maternal social capital. A total of 440 mothers coming to the selected health facilities for their child immunization services, and 22 experts including language experts, sociologists, social anthropologists, psychologists, and reproductive and child health experts were participated. In the process of tool development, we developed a draft a questionnaire based on existing literature. Then, experts in the field reviewed it. Finally, cognitive validation and psychometric properties of the tool was assessed. Descriptive statistics, correlation, and factor analysis were used to determine the psychometric characteristics of the tool, including item responses, internal consistency, and validity. Analyses were performed using SPSS version 23 software. The third paper assessed the uptake of maternal health services in the continuum of care and the role of social capital on the continuum of maternal health services. The required data were extracted from the Ethiopian Performance Monitoring for Action Maternal and Newborn Health study. The study was mainly conducted in six regions of Ethiopia including Tigray, Afar, Oromiya, Amhara, and Southern Nations, Nationalities, and Peoples‘ Region, and Addis Ababa. A total of 206 enumeration areas were selected using a multistage cluster sampling technique from the master sample frame of the Central Statistical Agency. All pregnant women and post-partum women (age 15–49) residing in households, located within the panel survey regions were asked to participate in the survey. The analysis was done on 2,664 women who completed the panel survey. Multilevel logistic regression was performed to account for dependence of observations within clusters. Data were analyzed using Stata version 17 software. Results: Four overarching themes and 13 sub-themes of social capital were identified as factors that improve uptake of MCH services. The identified themes were social networking, social norms, community support, and community cohesion. Most women, community health workers (CHWs) and religious leaders participated in social networks. These social networks enabled CHWs to create awareness on MCH services. Women, religious leaders and CHWs perceived that existing social capital improves the uptake of MCH services. A social capital assessment tool, which takes into account the cultural and social realities of south Gondar zone, northwest Ethiopia, was developed and validated. Five factors of structural social capital were extracted. These include group participation, emotional support, social support, financial support, and informational support. The content validity index of the scale was 0.88, which means that 88% of the experts rated the items of the scale as relevant. The loading of the items ranged from 0.505 to 0.858, exceeding the threshold of 0.50. For cognitive social capital, factor analysis grouped items into four subscales: trust in social networks, trust in institutions, trust in the health care system, and social cohesion. The loading of the items ranged from 0.507 to 0.913. The internal consistency reliability of the scale was excellent, with a Cronbach's alpha of 0.901. The proportion of women who received four or more antenatal care (ANC) visits, skilled birth attendance and postnatal care within two days was about 40%, 52%, and 34%, respectively. However, only 20.48% of women completed the continuum of care. Women who were encouraged by their partner to visit ANC were 2.12 times more likely to complete the continuum of care. In addition, women who had attended secondary school and above, women who lived in urban residence, households with the highest wealth quintile, who had experience with delivery complications, who wanted to have a baby, and counseling on all ANC components were significantly associated with completion of continuum of care. Conclusion: The community has an indigenous culture of emotional, instrumental and social support for women through social networks. It would be useful to consider the social capital of the family, neighborhood, and community as a tool to improve the use of MCH services. The Maternal Social Capital Assessment Tool is a valid and reliable instrument for measuring mothers' social capital during pregnancy, childbirth, and the postpartum period. The study also highlighted that women encouragement by their partners play a pivotal role for complete continuum of care. Therefore, policy makers should design people-centered health programs to involve existing social networks and religious leaders in improving MCH services. Interventions to empower women by improving their educational and wealth status are also needed. In addition, the application of such validated tool could enable the deciphering of the impact of social capital on maternal care. Keywords: Maternal and child health services; Social capital; Tool development; Ethiopia