Soil-transmitted helminthic infections are among the most common infections worldwide affecting the poorest and most deprived communities. The three major soil-transmitted helminths (STHs) are Ascaris lumbricoides, Trichuris trichiura and hookworm. This study was aimed to determine the prevalence of soil-transmitted helminthic infections and associated risk factors among schoolchildren in selected primary schools around Lake Tana, Bahir Dar, Ethiopia. A school based cross-sectional study was conducted from February 1, 2021 to May 12, 2021 G.C involving 337 study subjects. A systematic random sampling method was utilized to select the study participants from the selected schools. Data related to socio-demographic characteristics of the study participants and risk factors for STH infections were collected using a pretested questionnaire. Stool samples were collected in sterile plastic containers from each participant and processed using Ritchie‟s concentration and Kato-Katz thick fecal smear techniques at Bahir Dar University Biomedical Laboratory. The overall prevalence of STH infection was 38.3 % (129/337). Hookworm infection was the predominant STHs infection, which was detected in 88(26.1%) schoolchildren followed by Ascaris lumbricoides which infected 50 (14.8%) of the study subjects. Trichiuris trichiura was the least prevalent geo-helminthic infection and it was detected among five students (1.5%) only. Majority 115(34.1%) of the study subjects, had single infections. Double infection occurred in 14(4.2%) of study subjects. The sensitivity and specificity testing between the two methods, Ritchie‟s concentration techniques more preferable for Hookworm screening than A.lumbricoides and T.trichiura but Kato-Katz-technique was more effective for screening than Ritchie‟s concentration techniques for A.lumbricoides and T.trichiura detection. The common explanatory risk factors of STHs infection in the study subjects, among others, poor personal hygienic condition, less frequent shoes wearing habit, soil contact, occupation risk, and lack of hand washing habit before meal. Based on the result it could be concluded that STHs infection is a common problem among the schoolchildren around Lake Tana. Therefore, education on personal and environmental hygiene should be taken into account to reduce the prevalence of STHs infection. Moreover, schoolchildren and other risk group should receive regular deworming or treatment to control the transmission of STHs infections Keywords: Ascaris lumbricoides, Ethiopia, Hookworm, Lake Tana, Schoolchildren, Trichuris trichiura