Recent surveys suggest that the elderly are more frequent users of complementary and alternative medicines (CAMs) than the general population-up to 80% have reported using at least one CAM on a regular basis in the past year. Although many reasons are cited for their interest in CAMs, the elderly commonly state that CAMs are not used as 'alternatives', but rather as 'supplements' to compensate for aspects perceived to be lacking in conventional care. Although high-level evidence supports the use of some CAMs in specific conditions, their use in the elderly presents significant challenges as this population is burdened by polypharmacy, decreased functional reserve and chronic disease. Preventing adverse reactions and drug interactions associated with CAM use is complicated by the fact that fewer than 50% of older patients disclose CAM use to their doctor or pharmacist. This article is a guide for health professionals who wish to advise the elderly consumer on the rational use of CAMs. J Pharm Pract Res 2005; 35: 63-8.