Cystic breast lesions (CBLs) have been recognized as the most frequent female benign breast lesions. Complex cystic breast masses are suspicious findings that usually need biopsy. The aim of this study is to analyze the features of different types of cystic breast lesions at mammography and ultrasonography (US) and to determine its appropriate Breast Imaging Reporting and Data System (BI-RADS) categories. Thisis a prospective study, 25 patients with different types of CBLs were included. All lesions were subjected to mammography, uranography, Doppler internal vascularity and biopsy. The study was conducted for a period of one year from September 2020 to September 2021 and was approved by our institution's ethics committee. 25 different cystic breast lesions were found, six lesions (24%) were simple cysts, one lesion (4%) was clustered microcysts, seven lesions (28%) were complicated cysts, and eleven lesions (44%) were complex solid and cystic type. It was found that all simple, clustered microcysts and complicated cysts are benign, while 4 out of 11 complex cysts of the study were proved malignant. The PPVs for malignancy in simple, clustered microcysts and complicated cysts is 0%. While the PPVs for complex cyst was 36%. The accuracy of sonography in detecting and allowing correct diagnosis of breast cyst has been reported to be almost 100%. Complex cystic breast masses are suspicious ultrasound findings that usually need biopsy.