In this study, we aimed to investigate the effects of pentoxifylline (PTX) on male reproductive parameters in diabetic mice. Male adult mice (n = 24) were divided into control and three experimental groups (n = 6) including Diabetic, Diabetic + PTX and PTX groups. Diabetes was induced by single injection of streptozotocin (60 mg kg-1 ). PTX was administered intraperitoneally at the dose of 12 mg kg-1 for 14 days 1 week after diabetes induction. Serum levels of testosterone and blood glucose were determined and collected spermatozoa from cauda epididymidis analysed. Based on histological slides prepared from testis, the diameter of seminiferous tubules was determined using Motic camera and software and also apoptosis using TUNEL assay. Data were analysed using one-way anova method, and P < 0.05 was considered statistically significant. The mean of seminiferous tubules diameter, final body weight, testis weight, sperm parameters and testosterone hormone level in PTX-treated diabetic group indicated a significant increase compared to diabetic one, whereas apoptosis index and blood glucose were decreased in this comparison (P < 0.05). These results suggest that intraperitoneal administration of PTX is a potentially beneficial agent to reduce testicular damage and improves sperm parameters in diabetic mice by decreasing the ratio of apoptosis.