RESUMEN
Rosemary (Rosmarinus officinalis L. - Labiatae) is a plant in the treatment of urinary disorders, dysmenorhea and respiratory problems. Rosemary toxicity was evaluated in famale rats and an anti-implantation effect was reported after treatment with an aqueous extract of this plant. This works analyzes the effect of a short-term administration of R. officinalis aqueous extract on vital organs, on the organs of the reproductive system and sperm concentration of mature male Swiss mice. Treated animals received 260 mg/kg of body weight for five days. Body and organs weights, sperm production and food consumption were evaluated. This preliminary investigation reports that no body weight reduction and no toxic effect on the organd, gamete production or food intake were detected in any of the groups analyzed, given the experimental protocol used.