Background: The potent anti-inflammatory pharmacologic effects of the corticosteroids (cortisone and synthetic derivatives) has led to their extensive usage in the management of rheumatologic diseases and athletic musculoskeletal injuries. The efficacy and risks of locally injected or systemically administered corticosteroids in the treatment of athletic injuries are unclear. Objective: To review critically the medical literature and determine complications and risks associated with corticosteroid treatment of athletic injuries. Data Sources: A search of 3 databases-MEDLINE, CINAHL, and Cochrane Clinical Trial Register-was performed using the OVID interface for all years between 1966 and 2003. The search first combined all references under the medical subject headings adrenal cortex hormones, glucocorticoids, and glucocorticoids, synthetic. A second search combined all references under the medical subject headings athletic injuries, sprains and strains, tendon injuries, shoulder injuries, rotator cuff disease, tennis elbow, and lateral epicondylitis. The references identified by these 2 searches were intersected and limited to human only to produce 130 articles. Relevant review articles were scanned, references reviewed, and additional articles retrieved for consideration of inclusion. Study Selection: For inclusion in this critical review, articles must meet the following criteria: (1) subjects were human, (2) subjects had athletic-related injuries, and (3) subjects received corticosteroid treatment. Ultimately, 43 studies met inclusion criteria. Data Extraction and Synthesis: Selected articles were then categorized as to whether the primary focus was usage/efficacy of corticosteroid injection therapy, occurrence of complications of corticosteroid injection therapy, or usage or complications of systemic corticosteroid therapy. Main Results: Twenty-five selected studies primarily examined the usage/efficacy of corticosteroid injections in the treatment of various athletic injuries. Of the 983 total subjects who received corticosteroid injections among these studies, only minor complications of treatment were reported. Eighteen selected studies primarily described complications of corticosteroid injections in the treatment of athletic injuries. Of these, tendon and fascial ruptures were the predominant complications reported. The search identified no articles that addressed the usage of or complications of systemic corticosteroids in the treatment of athletic injuries, although tibial stress fracture and multifocal osteonecrosis occurred in individuals being treated for nonathletic injury conditions. Conclusions: This critical review reveals that the existing medical literature does not provide precise estimates for complication rates following the therapeutic use of injected or systemic corticosteroids in the treatment of athletic injuries. Tendon and fascial ruptures are often reported complications of injected corticosteroids, whereas tibial stress fractures and multifocal osteonecrosis were described with systemic corticosteroids.