We aimed to describe the approaches and characteristics of systematic reviews on three major complementary therapies and to assess their methodological quality.Systematic reviews of clinical trials of acupuncture, herbal medicines, and homeopathy were identified from a database developed for the Cochrane Collaboration Complementary Medicine Field. Information on conditions, interventions, methods, results, and conclusions was extracted using a pre-tested form; methodological quality was assessed using the Oxman scale.115 reviews were included (39 on acupuncture, 58 on herbal medicine, 18 on homeopathy). Research questions were most specific in herbal medicine, and tended to be very general in homeopathy. The main comparison in most reviews was with placebo. The methodological quality of reviews was highly variable. Deficiencies were most frequent for the description of the selection process and the summary of the results of primary studies.Systematic reviews tend to approach different complementary therapies in different manner. Compared to a set of reviews on analgesic interventions methodological quality was slightly better on the average, but there is ample room for improvement in future complementary medicine reviews.