Background/aim: In the prevention of periarticular heterotopic ossification (HO), a common complication after total hip arthroplasty (THA), nonsteroidal antiinflammatory drugs (NSAID) and irradiation are used. Some theories presume that local hypoxia of the soft tissue causes HO. The aim of this study was to investigate if the early use of pulsed electromagnetic fields (PEMF) could prevent this ossification since it accelerates the circulation and oxigenation of soft tissue. Methods. The study included three groups of the patients with primary THA. The group C consisted of 66 patients/79 hips who had only kinesitherapy in postoperative rehabilitation. The group B consisted of 117 patients/ 131 hips who had PEMF and interferential current (IC) which, on average, started on the 14th day after the surgery combined with the standard kinesitherapy. The group A consisted of 117 patients/131 hips who had PEMF from the third postoperative day and IC from, on average, the 14th postoperative day with the standard kinesitherapy. The classification of HO was done on a standard AP roentgenograms of the hips, taken at least one year after the surgery. Results. The overall HO was seen in 50.63% of the group C patients, in 43.51% of the B group and in 16.67% of the group A. Severe HO (III and IV class according to Brooker) was seen in 26.58% of the group C patients and in 6.10% of the group B, but none in the group A. Conclusion. According to the obtained results an early treatment with PEMF could prevent severe HO and reduce the overall HO.