The present investigation was carried out to assess the antifertility activity of ethanol extract of Bacolepis nervosa stem and leaf in male albino rats. Acute toxicity study of the extract was determined in adult male albino rats. The antifertility activity of ethanol extract at the dose levels 150 and 300 mg/kg orally was evaluated in experimental animal models and effect of extract on reproductive organs, sperm count, motility and sperm abnormality and fertility test were investigated. The treatment caused decrease in weight of testis, sperm count and revealed a reduction in the size of seminiferous vesicles. The epididymas sperm count, motility and sperm abnormality were reduced significantly in treated rats. When compared with control rats, B. nervosa extracts led to significant testosterone and lutinizing hormone suppression associated with consequent significant rise in estrogen. There was an increase in serum protein, albumin, globulin, urea, creatinine and the activity of liver marker enzymes (SGOT, SGPT and ALP) levels of control and treated rats. The activities of serum antioxidants (CAT, SOD, GPx, GST and GRD) in plant extract treated rats were decreased. The results of fertility test indicated that the treated adult male rats reduced the number of female impregnation. The results conclude the disruption of spermatogenic as well as androgenic compartment. The present study suggests that B. nervosa extracts suppress male fertility without altering the general metabolism.