Ulnar neuropathy at the elbow is the second most common entrapment neuropathy after carpal tunnel syndrome. Treatment may be conservative or surgical but optimal management remains controversial. This is an update of a review first published in 2010.To determine the effectiveness and safety of conservative and surgical treatments in ulnar neuropathy at the elbow.We searched the Cochrane Neuromuscular Disease Group Specialized Register (20 February 2012), CENTRAL (2012, Issue 2), MEDLINE (January 1966 to February 2012), EMBASE (January 1980 to February 2012), AMED (January 1985 to February 2012), CINAHL Plus (January 1937 to February 2012), LILACS (January 1982 to Feburary 2012), PEDro (January 1980 to February 2012), and the papers cited in relevant reviews.The review included only randomised controlled clinical trials (RCTs) or quasi-RCTs evaluating people with clinical symptoms suggesting the presence of ulnar neuropathy at the elbow. We included trials evaluating all forms of surgical and conservative treatments. We considered studies regarding therapy of ulnar neuropathy at the elbow with or without neurophysiological evidence of entrapment.Two authors independently reviewed titles and abstracts of references retrieved from the searches and selected all potentially relevant studies. The authors extracted data from included trials and assessed trial quality independently. They contacted trial investigators for missing information.We identified six RCTs (430 participants), with moderate quality evidence, for inclusion in the review. When the searches were updated in 2012 we found no further studies. The sequence generation was not adequate in one study and not described in two studies. We performed two meta-analyses to evaluate the clinical (three trials, 261 participants included) and neurophysiological (two trials, 101 participants included) outcomes of simple decompression versus decompression with submuscular or subcutaneous transposition.We found no difference between simple decompression and transposition of the ulnar nerve for both clinical improvement (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.80 to 1.08) and neurophysiological improvement (mean difference (in m/s) 1.47, 95% CI -0.94 to 3.87). In the simple decompression group 91 out 131 patients clinically improved; in the transposition group 97 out 130 patients improved. Transposition showed a higher number of wound infections (RR 0.32, 95% CI 0.12 to 0.85).In one trial (47 participants) the authors compared medial epicondylectomy with anterior transposition and found no difference in the clinical and neurophysiological outcomes.One trial (51 participants) assessed conservative treatment in clinically mild or moderate ulnar neuropathy at the elbow. The authors found that information on avoiding prolonged movements or positions was effective in improving subjective discomfort. Night splinting and nerve gliding exercises in addition to the information did not produce further improvement.The available evidence is not sufficient to identify the best treatment for idiopathic ulnar neuropathy at the elbow on the basis of clinical, neurophysiological and imaging characteristics. We do not know when to treat a patient conservatively or surgically. However, the results of our meta-analysis suggest that simple decompression and decompression with transposition are equally effective in idiopathic ulnar neuropathy at the elbow, including when the nerve impairment is severe. In mild cases, evidence from one small RCT of conservative treatment showed that information on movements or positions to avoid may reduce subjective discomfort.