Poor appetite is a common symptom among cancer patients. It can lead to inadequate food intake, weight loss, physical debilitation and reduced tolerance to anti-neoplastic treatment. Although cancer-induced anorexia is not fully understood, there are some theories relating to its development. Interventions may be aimed at improving nutritional intake to prevent excessive weight loss when poor appetite exists, or it may concentrate on improving appetite by pharmacological means. Appetite should be considered alongside other aspects of symptom control and tackled aggressively when it is contributing to a poor quality of life.