The aim of the present study was to study the effect of seeds of Asteracantha longifolia on the sexual behaviour of male albino rats. The ethanolic extract of seeds of A. longifolia was administered to groups of rats in 100, 150 and 200 mg kg⁻¹ doses for a period of 28 days, and the action compared with control rats. The changes in body and organ weight, sexual behaviour, histo-architecture and fructose levels of seminal vesicles were observed. The sexual behaviour was assessed by determining parameters such as mount frequency (MF), intromission latency, mount latency (ML) and post-ejaculatory latency. The ethanolic extract exhibited pronounced anabolic effects in treated animals, as evidenced by gains in the body and reproductive organ weights. Increased spermatogenesis due to treatment with extracts was also witnessed in transverse section. The treatment further markedly affected sexual behaviour of the animals, as reflected by the reduction of ML, increase in MF and enhanced attractability towards females. A significant increase in the sperm count as well as fructose levels of seminal vesicles was noted.