Triple pelvic osteotomy was performed for sequel of DDH including AVN between 1981 and 2002 for 329 patients (351 hips, 280 females, 49 males, average age at surgery 16.5 years, range 9-41 years, follow-up 4-25 years). A small modification of Steel's technique consisting of strictly subperiostal resection of segment from both pubic and ischial bone was used. Average gain of lengthening extremity was 1.8 cm. The average CE angle was improved from 7.8 to 35.5 degrees. Clinical results were evaluated according to Merle d'Aubigne and reflected to the preoperative clinical and radiological findings. There were 146 hip joints in 128 patients (76%) with excellent results in the group of congruent hips without arthrosis. In 182 hips in 178 patients with hip joints with some deformity, limited ROM and decentration, 40% were excellent, 32% good, 23% fair and 5% unsatisfactory results were achieved. The group of decentrated hip joints in young adults in incongruency, limited ROM and sometimes severe arthrosis consisted of 23 monolateral surgeries with 39% unsatisfactory, 39% fair and 22% good results, respectively. No major neurovascular complications were seen. Non-unions were recorded in 19 patients (5.4%), including 2 triple and 2 double non-unions. Based on our long-term experience, we can conclude that triple pelvic osteotomy according to Steel in our modification is a safe method and gives regularly excellent or good results for correction of clinical and radiographic appearance of acetabular dysplasia when there is a proper indication.