Cisplatin is a potent and a major anti-neoplastic drug in the treatment of a broad spectrum of malignancies. However, its clinical use is limited by renal tubular dysfunction that occurs in a significant percent of patients. The aim of the present study was to evaluate the possible protective effect of theophyline in the prevention of cisplatin-induced nephrotoxicity. The trial design was prospective, randomized, double-blinded and placebo controlled. Chemotherapeutic patients who received cisplatin at a dosage of at least 50 mg/m 2 alone or in combination with other chemotherapy agent(s) were included in the study. There were a total of 76 patients who were randomly divided into two groups. In group 1 (n = 38), placebo was advised; in group 2 (n = 38), patients received 4 mg/kg aminophyline as an intravenous loading dose, followed by theophyline in a dose of 200 mg three times daily orally for four consecutive days. The placebo group had 22 males and 16 females and the theophyline group had 26 males and 12 females. The mean age was 51 ± 17.6 years and the mean dose of cisplatin was 86.71 ± 43.18 mg. The prevalence of cisplatin nephrotoxicity in groups 1 and 2 was 7.9 and 5.3%, respectively, and the difference was not significant (P = 1). In addition, there was no significant association of cisplatin nephrotoxicity with age (P = 0.1), gender (P = 0.64) and mean dose of cisplatin (P = 0.8). These results indicate that prophy-lactic application of aminophyline and theophyline does not have a protective effect against cisplatin nephrotoxicity.