Objectives To assess the diagnostic accuracy of prenatal ultrasound in detecting intra‐abdominal masses derived from different systems. Methods Fetuses diagnosed with abdominal cystic masses during prenatal ultrasound were included in this study. The basic biological parameters of the fetus were measured in addition to the location of the cystic mass, the shape and size of the mass, the thickness of the cystic wall, dynamic changes, blood supply of the mass, and relationship with the surrounding organs. Whether the fetus also had other malformations was also recorded. Clinical data were followed up to 6 months after birth. Results Between January 1, 2019 and January 1, 2021, 247 fetuses were included, most of which contained renal/adrenal cystic masses (n = 93, 37.7%), followed by hepatobiliary system (n = 48, 19.4%), gastrointestinal tract (n = 45, 18.2%), reproductive system (n = 29, 11.7%), and ureter and bladder (n = 27, 10.9%) masses, respectively. The minority were masses in other systems (n = 5, 2.0%). The overall prenatal diagnostic accuracy was 90.7%. There were significant differences in each system (χ2 = 13.0, P < .05). The most accurate type of cyst was diagnosed from renal and adrenal (96.8%) cases, followed by ureter and bladder (92.6%) cases, gastrointestinal tract (91.1%), hepatobiliary system (85.4%), and reproductive system (82.8%). Other systems (60.0%) were the least accurate type. Conclusions A wide variety of cystic masses can be accurately detected in the fetal abdomen, and most of these lesions can be accurately diagnosed during pregnancy.