We conducted a survey to identify and rank side-effects perceived by 99 patients receiving cancer chemotherapy. Non-physical side-effects constituted 54% of the 15 most severe symptoms, and included the thought of coming for treatment, the length of time taken by treatment and having to have a needle. Major physical side-effects were vomiting, nausea and hair loss. Differences in ranking of severity of side-effects were evident when patient groups were divided by sex, age, marital status and domestic situation, as well as by diagnosis, treatment and response. Evaluation of patient perception of the severity of side-effects is an aid to striking the cost benefit balance when deciding whether to use cancer chemotherapy.