We performed a systematic review of the current literature to determine the efficacy and duration of intra-articular corticosteroid injection in reducing pain caused by knee osteoarthritis and to determine whether the type of corticosteroid used affected these results. Following an electronic search of multiple databases and a review of reference lists from various articles, we found six trials in five papers that compared corticosteroid versus placebo and four papers that compared different corticosteroids. Results of corticosteroid compared with placebo showed both a statistically and clinically significant reduction in pain at 1 week, with an average difference between groups of 22%. Two of four trials showed triamcinolone to be more effective in pain reduction than other corticosteroids. We concluded that intra-articular corticosteroids reduce knee pain for at least 1 week and that intra-articular corticosteroid injection is a short-term treatment of a chronic problem.