Background: Harmful cultural practice is a malpractice due to the culture of community or nation and can significantly influenced a woman's and neonates health during perinatal period. The burden and negative consequences of harmful cultural practices during perinatal period were dangerous for health if it was not prevented. There was no evidence regarding harmful cultural practices during perinatal period among women in this the study area. Objectives: The aim of the study was to assess the prevalence of harmful cultural practices during perinatal period and associated factors among women in Simada District, South Gondar, Northwest Ethiopia, 2022/23. Methodology: A community based cross sectional study design was conducted among 512 women in Simada district from February 13/2023 to March 02/2023. Simple random sampling method was used to select kebeles in the district. The study participants were selected by systematic random sampling method and data was collected by using pre-tested interviewer-administered questionnaires. The data was entered to Epi data version 4.6 and cleaned, analyzed by using SPSS version 25 software. Logistic regression was applied to identify association between independent variables and the outcome variable. Statically association was claimed based on the adjusted odds ratio (AOR) with its 95% CI and a p-value of ≤ 0.05 Result: From a total of 518 study participants, 512 women were participated in the study, making response rate of 98.84%. Overall prevalence of harmful cultural practices during perinatal period was 36.7%) with 95% CI=32.5-41.1). Women who had not ANC follow up (AOR=2.82(1.36-5.86), women who attended by untrained birth attendants (AOR=3.93(2.16-7.14), women who lived distance >5KM from health facility (AOR=2.30(1.40-3.79) and women who lack of awareness (AOR=2.19(`1.33-3.60) were more likely to practice the harmful cultural practices during perinatal period. On the other hand who women had history of pregnancy complication (AOR=0.19(0.05-0.70) were less likely to practice the harmful cultural practices during perinatal period. Conclusion and Recommendation: Above one third of mothers practiced the harmful culture Antenatal care follow up, distance from health, untrained birth attendants, history of pregnancy complication and awareness were significantly associated with harmful cultural practices during perinatal period. Attending ANC follow up and creating awareness about the effect of harmful cultural practices decrease the practicing the harmful culture. Key words: Harmful culture, Antenatal care, perinatal period, Simada district