This study analyzed the cause, rate, and risk factors of iliac crest bone graft donor site morbidity. All complications or problems, no matter how small, were sought to develop strategies of prevention. A wide range of major, 0.76% (Keller et al) to 25% (Summers et al) and minor complications, 9.4% (Keller et al) to 24% (Summers et al) has been reported. A consecutive series of 261 patients, whose bone graft harvest was done by one surgeon, was studied by chart review and a mail survey that was not conducted by the operating surgeon. The survey presented specific open-ended questions designed to uncover any complication/problem, no matter how small. Complications then were categorized as major or minor and subcategorized as acute or chronic. Statistical analysis was done using chi-squared and multiple logistical regression. None of the 261 patients had a severe perioperative complication--e.g., superior gluteal artery injury, sciatic nerve injury, or deep wound infection. None of the 225 patients with long term follow-up (average, 66 months; range, 32-105 months) had a severe late complication--e.g., donor site herniation, meralgia paresthetica, pelvic instability, or fracture. Of the 180 patients meeting the qualifications for statistical analysis, major complications occurred in 18 (10%), only three of which affected function (pain). Minor complications occurred in 70 (39%). The results indicated that severe complications from iliac crest bone graft harvest can be avoided and major complications affecting functioning are uncommon, but minor complications are common. The findings suggest that procedural refinements of limiting subcutaneous dissection and providing layered tension-free incision closure may improve results.