Abstract: In this study, the effects of exposure to a 950MHz electromagnetic field (EMF) emitted from cellular phones on serum testosterone and cortisol hormones rate of adult male Syrian Hamster were evaluated. Seventy two male Hamster in 3 groups include: group 1 or control group, group 2 or expose for 10 days and under 950 MHz EMF (emitted from Cellular Phone) for 1 h daily group 3 or expose for 50 days and under 950 MHz EMF for 1 h daily. In final, blood samples collected for determine of the testosterone and cortisol concentration in the serum. Results showed that in long term exposure EMF (group 3) testosterone and cortisol levels were increased (p<0.01), but both of cortisol and testosterone hormones in short term EMF exposure (group 2) did not significantly change. In conclusion, long-term exposure of cellular phones EMF may affect the reproductive activity and impair endocrine homeostasis and it may cause peripheral effects.