Many cancer patients search the World Wide Web for information on CAM. The aim of this study was to evaluate the quality of such information and identify the treatments most frequently discussed. A pretested search strategy was employed to identify the websites that are most likely to be used by cancer patients and assess them according to predefined criteria. Thirty-two websites were included in this analysis. The quality of these sites was scored on a point system and varied between 8 and 14 points, with a maximum of 14. Most sites issued recommendations for a plethora of treatments, which are typically not supported by sound scientific evidence. Three sites had the potential for harming patients through the advice issued. The most frequently discussed therapies were herbal medicines, diets and mind–body therapies.