The 17α-hydroxylase/17, 20-lyase deficiency (17-OHD) is a rare disease. The clinical characteristics and gene mutation of 2 late-diagnosed 17-OHD patients with testicular tumor admitted to our hospital from March 2018 to February 2019 were analyzed retrospectively. The two 17-OHD patients were female (46, XY). Laparoscopic abdominal exploration found undeveloped testicles in grey-yellow or grey-red in the groin and iliac fossa. The testicles were removed and showed malignancy in pathology study. Sequencing of the CYP17A1 gene identified c.1247G>A/c.1427T>C and c.985_987delTACinsAA/c.1306G>A complex heterozygous mutations. Taking together, the possibility of 17-OHD should be considered in patients with hypertension, hypokalemia, adrenal adenomatoid hyperplasia together with 46, XY gonadal dysplasia, so as to make early diagnosis and treatment, and avoid dysplastic testicular turning to malignancy.