The phytochemical constituents of aqueous extract of Bulbine natalensis (Baker) stem and its effect on male rat sexual behaviour were evaluated for 7 days. Phytochemical screening revealed the presence of saponins, cardiac glycoside, tannins, alkaloids and anthraquinones. Administration of the extract at the doses of 25 and 50 mg/kg body weight resulted in the significant increase (p < 0.05) in mount frequency, intromission frequency, ejaculatory latency, ejaculation frequency, serum testosterone and luteinizing hormone concentrations, computed indices of sexual behaviour, erection, quick flips, long flips and total penile reflexes whereas the mount latency, intromission latency and post-ejaculatory interval were significantly decreased (p < 0.05) throughout the experimental period. The 100 mg/kg body weight of the extract produced contrasting pattern to the lower doses of the extract in all the parameters of sexual behaviour monitored throughout the experimental period. The results are indicative of prosexual stimulatory potentials of Bulbine natalensis in male rats. The aqueous extract of Bulbine natalensis stem at these doses (25 and 50 mg/kg body weight) may be used in the management of disorders of desire/libido, premature ejaculation and erectile dysfunction in males.