Subacromial impingement syndrome (SIS) is one of the most frequent shoulder pathologies. Initial treatment is conservative. Subacromial injection of drugs achieves a high concentration at the pathologic site with less drug use and fewer systemic side effects. Glucocorticoids are most frequently injected. One concern with steroid use is the wide array of potential systemic and local complications. Nonsteroidal anti-inflammatory drugs (NSAIDs) are also peripherally acting and can be used locally. Although intraarticular (IA) use of NSAIDs is common in orthopedic practice, it is mostly restricted to the knee joint. Reports of local NSAID for joint pathologies are relatively rare. This study compared the efficacy of single-dose subacromial injections of betamethasone and lornoxicam for treatment of SIS.