Abstract Background The effect of duty hour (DH) restrictions on postgraduate residents' acquisition of clinical competencies is unclear. We evaluated the relationship between DHs and competency‐related knowledge acquisition using the General Medicine In‐training Examination (GM‐ITE). Methods We conducted a multicenter, cross‐sectional study of community hospital residents among 2019 GM‐ITE examinees. Self‐reported average DHs per week were classified into five DH categories and the competency domains were classified into four areas: symptomatology and clinical reasoning (CR), physical examination and clinical procedure (PP), medical interview and professionalism (MP), and disease knowledge (DK). The association between these scores and DHs was examined using random‐intercept linear models with and without adjustment for confounding factors. Results We included 4753 participants in the analyses. Of these, 31% were women, and 49.1% were in the postgraduate year (PGY) 2. Mean CR and MP scores were lower among residents in Category 1 (