Study aimed to investigate the acute effect of temperature (at 39ºC, 41ºC and 43ºC) on male gametocytes of the Rattus norvegicus. Experimental animals were divided into four sets as; control and remaining three were experimental groups. After completion of exposure period, all animals were sacrificed; semen sample was collected from epididymis. The sample was assessed for qualitative and quantitative analysis of sperm. The sperm count was carried out by using Neubauer's counting chamber. Results obtained were discussed in relation to sperm morphometry and fertility of experimental animal.