We performed modified Z-plasty (N-plasty) in the patients with snapping hip syndrome arising from the iliotibial band whose pain and clicking sensation persisted despite conservative treatments. We analyzed clinical results to evaluate the effectiveness of this new technique. Among 51 patients (65 cases) who still felt pain and reported clicking sensation during daily life despite hospitalization for at least 2 months from January 1999 to November 2011, we evaluated a total of 32 patients (37 cases) who underwent N-plasty and followed up for more than 6 months. All patients were male whose average age was 24 years. Initial symptoms developed an average of 10 months before hospital visit. Surgery was defined success by postoperative 6 months at which time the patient could be able to carry on with daily life and to exercise without clicking sensation and pain, and defined failure when either clicking sensation or pain was present. We observed that the posterior portion of the iliotibial band was thickened by an average of 8.4 mm. Tenotomy of the iliotibial band lengthened the band by an average of 23mm and narrowed the width of the iliotibial band anterior to posterior. Success was in 33 cases (89%) after surgery. Failure was observed in 4 cases. Three were improved after resurgery and 1 was treated conservatively. We found that N-plasty performed in external type snapping hip patients was an effective method yielding a high success rate.