The present investigation was carried out on twenty eight mature male albino rats from laboratory animal unite in the faculty of veterinary medicine, Zagazig University, Egypt. The rats were divided into four equally groups; I, II, III and IV of seven rats for each. Group I & II are control groups but the group I was kept in normal day condition and group II was kept in 12 hours Light / 12 hours dark cycle during the period of experiment without exposure to electromagnetic field (EMF), at constant temperature about 25 C0. Group III was exposed to 50 Hz, 1 Gauss electromagnetic field (EMF) consciously for 21 days. Group IV was kept for 48 days post the end of the exposure period; 21 days and then complete to 48 days without exposure to MF for studying the delayed effects of MF exposure (reversibility or irreversibility). At the end of experiment, all groups were scarified by cervical dislocation and the liver, testis and kidneys were separated immediately and small pieces from them were taken, fixed in 10 % neutral buffered formalin, processed till paraffin sections and stained histologically with Hematoxylin and Eosin (H&E) and Green Masson’s Trichrome. Groups I, II showed normal histological structure of liver, testis and kidney without any abnormalities. Group III showed severe pathological lesions in the liver, testis and kidney. Regarding group IV, the histological examination of all organs showed the same normal histological structure as that in the control groups (I, II).