The effect of ethanolic extract of Fagara tessmannii, wide medicinal plants used on reproductive function in South Cameroon, was investigated in male rats. Twenty male sexually experienced rats (four groups) were orally treated with vehicle, 0.01, 0.1, 1gkg -1 BW per day of F. tessmannii (equivalent to 16.67g, 33.33g, 50g, 66.66gkg -1 dry raw material) for 14days, the upper limit dose without any clinical sign of toxicity was 2gkg -1 . Fagara tessmannii extract negatively affected weight of accessory organs and significantly affected body weight gain at dose 1gkg -1 (P<0.05) in treated rats. The weight of epididymis and seminal vesicle significantly decreased at low doses (0.01gkg -1 ) while the prostate weight decreased at all doses (P<0.05). The transit of spermatozoa in cauda epididymidis significantly increased at lower dose of 0.01gkg -1 (P<0.05). In addition, F. tessmannii extract affected neither daily sperm production (DSP) and DSP per g nor sperm count in vas deferens and epididymis. The length of stages IX-I of the seminiferous tubule and serum testosterone level increased dose-dependently following 14days of treatment (P<0.05). The results suggest that F. tessmannii, 14days after treatment, may improve spermatogenesis, testosterone level and sperm transit in cauda epididymidis but negatively impair reproductive organ activities. © 2011 Blackwell Verlag GmbH.