 Oral nutritional supplements (ONS) are commonly prescribed to malnourished patients to improve their nutritional status. Taste and smell changes in patients with cancer can affect the palatability of ONS. The present study investigated: (1) the palatability of six ONS in testicular cancer patients before, during the first two cycles, and after chemotherapy; (2) the relation between the palatability and taste and smell function; (3) the metallic taste of these ONS.