OBJECTIVES To investigate the occurrence and patterns of de novo malignancy in a series of kidney transplantation (KT) recipients in southern Taiwan. METHODS A retrospective study of 108 KT recipients who underwent follow-up at our hospital from 1991 to 2004 was carried out. The occurrence and patterns of malignancy were assessed. RESULTS Malignant growth was noted after transplantation in 9 patients (8.3%) and occurred 2 months to 7 years postoperatively, with an average of 4.1 years. There were 6 cases of urinary tract transitional cell carcinoma and 1 each of stomach, liver, and cervical cancer. The mean age at diagnosis of cancers was 54 years (range, 47 to 69 years); 1 patient with cancer was male, 8 were female. No skin cancer or lymphoma was detected in our transplant recipients. Compared with the KT patients without cancer, older age at KT, female recipient, and low educational status were the significant risk factors for the development of de novo cancers in our KT recipients (P <0.05). There were 3 deaths (50%) from urothelial carcinoma. CONCLUSIONS Urinary tract transitional cell carcinoma was the main de novo cancer among KT recipients in southern Taiwan. Older age at KT, female recipient, and low educational status were the significant risk factors for the development of de novo cancers.