The response rate to the treatment of obsessive compulsive disorder (OCD) is 21.6% to 61.3%, which shows a relative resistance to current treatments and a need for novel therapeutic approaches. Here we report a case of resistant OCD with fast and dramatic response to a relatively new method of repeated transcranial magnetic stimulation. In this method a pulse magnetic field emits from a coil over the surface of the scalp to induce a localized electrical current in the cortex below. Cortical activity can then be either inhibited or stimulated. The patient was a 40-year-old woman with severe OCD who admitted to our psychiatric hospital. She was treated with 10 sessions of rTMS (110% intensity, 1 Hz frequency and duration of 30 minutes per day / a total of 1200 pulses per day) on right supplementary motor area. Her improvement evaluated serially with Yale Brown Scale. By the end of the 2nd day she reported a major improvement of symptoms. Dramatic improvement was observed in her obsessive and compulsive behaviors, and avoidance recovered completely. She also reported significant improvement in ability to control obsessive thoughts and impulses, and anxiety symptoms. Since repeated transcranial magnetic stimulation is a low risk method with almost no interaction with the common medications, as well as the faster response obtained by using this method, it can be used as an add-on treatment in resistant cases of OCD and even in the initial stages of this disorder.