Introduction: The increasing use of EMF (electromagnetic field) generating apparatus (refrigerators, computers, TV, etc) caused an increasing interest in investigations of its adverse effects on human health. This study is done to investigate the effects of EFM on Balb/c mice.

  Materials and Methods: This is an experimental study in which at first a circuit generating low frequency electromagnetic field (50 Hz, 15G) was designed. Then adult virgin female mice were placed in coil and exposed to 15 gauss electromagnetic field for 4 day and 6 hour per day. Then their blood was examined to assay the level of hormones (FSH, LH, estradiol, progesterone). Also ovary and uterus sections were studied with light & electronic microscope.

  Results : Results showed that the weight and size of ovary was not significantly affected in females exposed to the low frequency electromagnetic field and their offspring. Our results also showed that the number of ovary follicles were significantly affected in exposed females (p<0.05). Also the study of micrographs showed hetrochromatinated oocytes and follicular cells and increasing polysomes, accumulation of mitochondria and cleft nucleus. Decreasing amount of FSH, LH and 50% decrease in couplation rate was also seen as compared with the control group.

  Conclusion: Results of this study is indicator of EFM effects on gonads^, structure and endocrine system and decreases fertility.