Abstract: The present study investigated the effect of electromagnetic field (EMF) radiated from mobile telephones with frequency equals 900 MHz on some liver enzymes, testosterone hormone and histological structure of liver and testis organs in albino rats after exposing them to the electromagnetic field for 3 and 6 months. Wistar rats were divided into three groups: I- control animals (10 animals) without near source of EMR, II- rats constantly exposed to EMR (20 animals) for 3 months and III-rats exposed to EMR (20 animals) for 6 months. Rats were exposed to 900 MHz continuous RF/MW fields for 1 h daily, 7 days/week. Results showed that electromagnetic field exposure caused a significant decrease in Albumin and testosterone hormone but the significant increases in Serum aminotransferase ALT, aminotransferase AST and total bilirubin were recorded. After three and six months of phone radiation exposure, there were the more severe fatty vacuolation, dilated portal vein and infiltration of a large amount of inflammatory cells with the sinusoids were moderately obliterated in liver, also, there were severing spermatogenic cells in some of the seminiferous tubules and major edema in the interstitial tissues and histopathological change's severity are increasing with the increase the time. Based on this animal model study, such effects are also expected in humans; therefore, it is suggested that long term and/or excessive use of mobile phones should be avoided. This can be achieved by health promotion activities such as group discussions, public presentations and through electronic and print media sources.