The management of symptoms experienced by patients receiving cytotoxic chemotherapy influences quality of life during treatment. Symptom management may be improved through a structured approach to symptom assessment. This paper describes the development of the Chemotherapy Symptom Assessment Scale (C-SAS), a 24-item scale designed for the routine assessment of symptoms experienced by patients receiving cytotoxic chemotherapy. The scale development process focused both upon the psychometric properties and the clinical usefulness of the scale. Patients and health professionals played a significant role in item selection and scale design in order to maximise the clinical utility of the C-SAS.