The main goal of this study was to evaluate the possible effects of electromagnetic field (EMF) of transmission lines exposure on testis tissue of mice. Forty adult BALB/c mice were divided into two groups. One group (twenty mice) has been done by daily exposures of 24 hours, and the other sham-exposed group (twenty mice) served as the control. After seven weeks of exposure, two groups of the mice were sacrificed. The testis tissue was assessed by serum biochemical assay, histopathological examination and flow cytometric analysis (FCM). EMF exposure did not significantly affect the distribution of DNA ploidy (1n, 2n and 4n cells), but significantly decreased the S phase fraction and the Proliferation Index of testis germ cells.