Background Pentavalent antimonial drugs are the most prescribed treatment for American cutaneous and mucocutaneous leishmaniasis. Other drugs have been used with varying success. Objectives To assess the effects of therapeutic interventions for American cutaneous and mucocutaneous leishmaniasis. Search strategy We searched the Cochrane Skin Group Specialised Register (January 2009), the Register of Controlled Clinical Trials in The Cochrane Library (Issue 1,2009), MEDLINE (2003 to January 2009), EMBASE (2005 to January 2009), LILACS (from inception to January 2009), CINAHL (1982-May 2007) and other databases. Selection criteria Randomised controlled trials (RCTs) assessing treatments for American cutaneous and mucocutaneous leishmaniasis. Data collection and analysis Two authors independently assessed trial quality and extracted data. Main results We included 38 trials involving 2728 participants. Results are based on individual studies or limited pooled analyses. There was good evidence in: Leishmania braziliensis and L. panamensis infections: Intramuscular (IM) meglumine antimoniate (MA) was better than oral allopurinol for 28 days (1RCT n= 127, RR 0.39; 95% CI 0.26, 0.58). Intravenous (IV) MA for 20-days was better than 3-day and 7-day IVMA plus 15% paromomycin plus 12% methylbenzethonium chloride (PR-MBCL) or 7-day IVMA (1RCT n= 150, RR 0.24; 95% CI 0.11, 0.50; RR 0.69; 95% CI 0.53, 0.90; RR 0.64; 95% CI 0.44, 0.92 respectively). Oral allopurinol plus antimonials was better than IV antimonials (2RCT n= 168, RR 1.90; 95% CI 1.40, 2.59; I-2= 0%). L. braziliensis infections: Oral pentoxifylline plus IV sodium stibogluconate (SSG) was better than IVSSG (1RCT n= 23, RR 1.66; 95% CI 1.03, 2.69); IVMA was better than IM aminosidine sulphate (1RCT n= 38, RR 0.05; 95% CI 0.00, 0.78) and better than IV pentamidine isethionate (1RCT n= 80, RR 0.45; 95% CI 0.29, 0.71). Intramuscular MA was better than Bacillus Calmette-Guein (1RCT n= 93, RR 0.46; 95% CI 0.32, 0.65). L. panamensis infections: Oral allopurinol was better than IVMA (1RCT n= 58, RR 2.20; 95% CI 1.34, 3.60). Aminosidine sulphate at doses of 12mg/kg/day and 18mg/kg/day for 14 days were better than aminosidine sulphate 12mg/kg/day for 7 days (1RCT n= 60, RR 0.23; 95% CI 0.07, 0.73; RR 0.23; 95% CI 0.07, 0.73 respectively). Oral ketoconazole for 28 days, oral miltefosine and topical PR-MBCL were better than placebo. Authors' conclusions Most trials have been designed and reported so poorly that they are inconclusive. There is a need for large well conducted studies that evaluate long-term effects of current therapies to improve quality and standardization of methods.