Methotrexate (MTX) is a chemotherapeutic agent causing defective oogenesis and spermatogenesis. This study was performed to assess the role of human growth hormone (GH) on testis recovery after treatment with MTX. Forty male Wistar rats were selected and randomly divided into four groups (n = 10): control (vehicle), GH group (0.3 mg kg(-1) GH for 28 days, IP), MTX group (MTX 1 mg kg(-1) week(-1) for 4 weeks, IP) and GH/MTX group (0.3 mg kg(-1) GH for 28 day plus 1 mg kg(-1) week(-1) MTX for 4 weeks, IP). On days 14 and 28, five rats from each group were killed, testes of rats of all groups were removed, spermatozoa were collected from epididymis and then prepared for analysis. MTX caused significant increase in interstitial tissue and capsular thickness and decrease of testicular and body weight (P < 0.05). Moreover, it caused significant decline in seminiferous tubule diameter and epithelium thickness (P < 0.05). There was no obvious change in morphometrical parameters between MTX/GH and control groups. In MTX group, sperm parameters decreased significantly (P < 0.05). Administration of GH plus MTX reduced the effects of MTX on sperm parameters and testosterone concentration. These results suggested that GH had a protective effect on almost all destructive effects caused by MTX in rat testes and thus improved sperm parameters.