Objective: To determine the frequency of congenital malformations diagnosed by prenatal ultrasound in the “Dr. Freddy Guevara Zuloaga” Perinatology Unit of the University Hospital of Caracas, Venezuela, in the period between January 1, 2015 and December 31, 2020. Methods: Retrospective, descriptive, cross-sectional study. The statistical records of the Unit were reviewed, with a population of 56,712 and 1844 patients were included in accordance with the inclusion criteria. Results: A general prevalence of 3.3% was obtained. The largest number of studies was conducted in 2016 (12,781). The highest prevalence of congenital malformations was 4.6%, in 2018. In order of frequency, the affected systems were: central nervous system, cardiovascular, genitourinary, gastrointestinal and abdominal wall. Less frequently, abnormalities of the face and neck, chest and lung, musculoskeletal system, and tumors were diagnosed. The most frequent malformations were: pyelic dilation (152 / 8.2%), ventriculomegaly (143 / 7.6%), gastroschisis (114 / 6.1%), Arnold Chiari type II (71 / 3.8%), acraniaexencephaly sequence (66 / 3.5%) and ventricular septal defect (64 / 3.4%). Conclusion: The frequency of congenital malformations diagnosed by ultrasound was 3.3%. The most frequently affected areas were the central nervous, cardiovascular and genitourinary systems.