Fibromyalgia (FM) is a syndrome expressed by chronic widespread pain often associated with reduced physical function. Exercise is a common recommendation in management of FM. We evaluated the effects of exercise training on global well-being, selected signs and symptoms, and physical function in individuals with FM. We searched Medline, Embase, CINAHL, SportDiscus, PubMed, PEDro, and the Cochrane Central Register for Controlled Trials to July 2005 and included randomized trials evaluating cardiorespiratory endurance, muscle strength, and flexibility. Methodological quality was assessed using the van Tulder and Jadad instruments. Training protocols were evaluated using American College of Sports Medicine (ACSM) guidelines. Clinical heterogeneity limited metaanalysis to 6 aerobic and 2 strength studies. There were 2276 subjects across the 34 studies; 1264 subjects were assigned to exercise interventions. Metaanalysis of 6 studies provided moderate-quality evidence that aerobic-only exercise training at ACSM-recommended intensity levels has positive effects on global well-being (SMD 0.49, 95% CI 0.23-0.75) and physical function (SMD 0.66, 95% CI 0.41-0.92) and possibly on pain (SMD 0.65, 95% CI -0.09 to 1.39) and tender points (SMD 0.23, 95% CI -0.18 to 0.65). Strength and flexibility remain underevaluated; however, strength training may have a positive effect on FM symptoms. Aerobic-only training has beneficial effects on physical function and some FM symptoms. Strength-only training may improve FM symptoms, but requires further study. Large, high-quality studies of exercise-only interventions that provide detailed information on exercise prescription and adherence are needed.