The objective of this experiment was to investigate the ameliorative effect of vitamin E (Vit E) on tissue damage caused by heat stress in the testes of broilers, and to correlate this effect with the secretion of the HSP-70 protein. In the study totally 30 broilers (breed Ross 308) were used. Animals were divided into three groups, including the control group. Group Control (C); these broilers (24 degrees C) were not administered with Vit E in the diet and not subjected to heat stress. Group Stress (S); these broilers not administered with Vit E in the diet but subjected to heat stress (34 degrees C). Group Stress + Vitamin E (Group S + vit E); broilers subjected to heat stress (34 degrees C) and administered with vitamin E. Histopathological examination demonstrated the presence of degenerative alterations in testes tissue of the group S. However, there has been seen diminishing the severity of degeneration in the group S + Vit E. While secretion of HSP-70 was determined in the testes of all groups in varying degree, the highest secretion level of HSP-70 was in the group C, the lowest secretion level of HSP-70 was in the group S. It is concluded that heat stress reduces the secretion of HSP-70 in testes of broilers, when vitamin E is administered, the secretion of HSP-70 increases again and reduces tissues damage.