Intramuscular injection(IM) into the gluteal muscles is a common route of medication, but may lead to complications. A retrospective review of 32 patients who required surgical treatment for local complications of buttock injections in children was made at the Taegu Fatima Hospital during a seven-year ninemonth period (March 1990 to December 1997). Local complications included acute inflammation, cellulitis and abscess(71.9 %), and fat necrosis(21.9 %), and injection granuloma(6.2 %). Over the half of injections were on the upper and outer quadrant of the buttock, but the other 43.7 % were in the upper and inner or lower and outer quadrant which are considered unsuitable sites for intramuscular injection. The majority of complications developed within fat tissue (90.6 %) rather than within muscle(9.4 %). Two-thirds of the patients were under 2 years of age, this suggests that it is technically difficult to accurately administer 1M injections in small children because muscle mass is smaller compared to subcutaneous. In addition subcutaneous fat is more susceptible to chemical irritation. Staph. aureus was the predominant organism, isolated in 84.6 % of the patients with abscesses. Treatment consisted of needle aspiration, incision and drainage, curettage, or surgical excision. In conclusion, the major factor that contributes to complications following 1M of the buttock appears to be the inadvertent intrafat rather than of 1M injection. Accurate injection into the muscles based on a knowledge of pelvic anatomy as well as the potential complications is necessary to prevent complications.