Single-incision laparoscopic cholecystectomy (SILC) may offer advantages over conventional laparoscopic cholecystectomy (LC). MEDLINE, Embase, PubMed, CINAHL, Cochrane Central Register of Controlled Trials and the Cochrane Library were searched for randomized clinical trials on SILC versus LC until May 2012. Odds ratio (OR) and weight mean difference (WMD) were calculated with 95 per cent confidence intervals (c.i.) based on intention-to-treat analysis. Thirteen randomized clinical trials included a total of 923 procedures. SILC had a higher procedure failure rate than LC (OR 8·16, 95 per cent c.i. 3·42 to 19·45; P < 0·001), required a longer operating time (WMD 16·55, 95 per cent c.i. 9·95 to 23·15 min; P < 0·001) and was associated with greater intraoperative blood loss (WMD 1·58, 95% of c.i. 0·44 to 2·71 ml; P = 0·007). There were no differences between the two approaches in rate of conversion to open surgery, length of hospital stay, postoperative pain, adverse events, wound infections or port-site hernias. Better cosmetic outcomes were demonstrated in favour of SILC as measured by Body Image Scale questionnaire (WMD -0·97, 95% of c.i. -1·51 to -0·43; P < 0·001) and Cosmesis score (WMD -2·46, 95% of c.i. -2·95 to -1·97; P < 0·001), but this was based on comparison with procedures in which multiple and often large ports (10 mm) were used. SILC has a higher procedure failure rate with more blood loss and takes longer than LC. No trial was adequately powered to assess safety.