BackgroundCo-infection of malaria with helminths poses significant risks including fetomaternal hemorrhage, fetal growth retardation, spontaneous abortion, and preterm delivery. However, there is a lack of community studies to demonstrate the prevalence of co-infection of helminths with Plasmodium and soil-transmitted helminths and associated factors among pregnant women in Ethiopia. MethodsA community-based cross-sectional study was conducted among 287 randomly selected pregnant women in the Abaya district from September to December 2022. Data were collected using a standardized questionnaire. Blood and stool samples were collected from each pregnant woman and data analysis was performed using SPSS for data analysis. Logistic regression analysis was used to identify associated factors. ResultsThe prevalence of co-infection with Plasmodium and soil-transmitted helminths was 19.5% (95% CI: 14.92%-24.08%) where soil-transmitted helminths were 40.6 %(95% CI: 34.9%-46.3%) and Plasmodium was 32.4% (95% CI: 27%-37.8%). Hookworm and P. falciparum were the most commonly identified parasite species. Factors significantly associated with co-infection with Plasmodium and soil-transmitted helminths included the habit of eating soil (AOR= 2.70, 95% CI: 1.36-5.34), not using insecticide-treated bed nets (AOR=3.47, 95% CI: 1.76-6.85), living near stagnant water (AOR= 2.23, 95% CI: 1.07-4.64), and rural residence (AOR= 2.23, 95% CI: 1.07-5.97). ConclusionsInterventions should prioritize enhancing sanitation, educating pregnant women on the use of insecticide-treated bed nets, avoiding eating soil, and eliminating stagnant water near homes. More research should be conducted on the area using more advanced methods.