Undescended testis is a common problem leading to infertility. After orchiopexy some studies support the necessity of hormonal therapy. Electromagnetic field stimulation on living tissues increase cell proliferation, protein and DNA synthesis. Sixteen prepubertal rats was objected to the fixation of left testes to the anterior abdominal wall for 30 days, right testes were removed. Another group of sixteen rats objected only to the right orchiectomy and a manipulation simulating study group without fixation. After orchiopexy, animals were divided into two groups. Both groups had eight rats. Electromagnetic field (EMF) stimulation group had the stimulation for two hours every day for ten days, while the second group did not. The sham group also divided into two groups. The first one applied EMF and name as Group CEM, the second one was sham. Weight of removed testes were measured and fixed in 10% formaldehyde for histopathological evaluation. At the creating of undescended testis and right orchiectomies a blood sample was obtained for testosterone level of prepubertal rats. After finishing EMF stimulation the rats were mated with females for 17 days. After fertility study a blood sample was obtained for testosterone assay and body weight were measured and fixed in formaline for histopathologic evaluation. All the rats were killed with overdose ether anesthesia and number of fetuses were recorded. Histopathological evaluation was based on Johnsen criteria and seminiferous tubule diameter measurements. We conclude that EMF stimulation resulted in Leydig cell proliferation, increase in testosterone level, testis weight, but decrease in germ cell population.