Objectives: This study aimed to assess the prevalence and configuration of C-shaped canal morphology in maxillary molars in an Iranian population residing in Kermanshah Province of Iran using cone-beam computed tomography (CBCT). Materials and Methods: This cross-sectional study was conducted on 2290 CBCT scans of 804 maxillary first molars, 1049 maxillary second molars, and 437 maxillary third molars. The Maxillary Upper-C Classification System was used for the detection of C-shaped canal morphology, and the classification by Jo et al. was used for assessment of the configuration of C-shaped canals. Data were analyzed by the Chi-square test (alpha = 0.05). Results: The prevalence of C-shaped canals in the maxillary first, second, and third molars was 1%, 7%, and 9%, respectively. Type III other types (B-P) was the most frequent configuration followed by type I subtype C (MB-DB). The prevalence of C-shaped canal morphology was not significantly different among different age groups (p >0.05); however, its prevalence in females was almost twice that in males (p <0.05). The prevalence of C-shaped canals was not significantly different in the right and left quadrants (p=0.099). The most frequent configuration was type I subtype B (DB-P) in males, and type III other types (B-P) in females (p=0.364). Conclusion: The prevalence of C-shaped canals in maxillary first, second, and third molars was 1%, 7%, and 9%, respectively. C-shaped canals were more common in females, and type III other types (B-P) was the most frequent configuration in our study population.