The suspension of the extract of Ocimum gratissimum Linn. was administered orally at the dose of 100, 250, and 500 mg / kg body weight, to different groups of male rats (n = 6) once a day for seven days. The female Swiss Albino mice involved in mating were made receptive by hormonal treatment. The general mating behaviour, libido and potency were determined and compared with the standard reference drug sildenafil citrate. The probable gastric ulceration and adverse effects of the extract were also evaluated. Oral administration of the extract significantly increased the Mounting Frequency, Intromission Frequency; Intromission Latency, Erections as well as aggregate of penile reflexes and caused significant reduction in the Mounting Latency and Post Ejaculatory Interval. The most appreciable effect of the extract was observed at the dose of 500 mg/kg. The test drug was also found to be devoid of any conspicuous gastric ulceration and adverse effects. The results indicated that the ethanolic extract of Ocimum gratissimum produced a significant and sustained increase in the sexual activity of normal male mice. Thus, the resultant aphrodisiac effectivity of the extract lends support to the claims for its traditional usage in sexual disorders.