28 RCTs (n=1745) were included in this systematic review to compare the benefits and harms of low- and high-energy extracorporeal shockwave therapy (ESWT), and to compare ESWT to placebo and other treatments, for the treatment of calcific and noncalcific tendinitis. Additionally, treatment effects between calcific and noncalcific conditions were compared. Results indicated statistically significant improvements in shoulder pain, function and calcification resolution for high-energy ESWT over placebo but only significant benefits in function for low-energy ESWT over placebo. Shoulder function was significantly better with high-energy ESWT versus low-energy ESWT while pain outcomes were similar. ESWT did not appear to affect outcomes in noncalcific tendinitis. Comparisons between ESWT and other treatments were infrequent.