This study aimed to define and prioritize the need for specialist palliative care (SPC) in cancer outpatient clinics. A validated assessment tool, the Symptoms and Concerns Checklist, was used to determine the prevalence and severity of symptoms and concerns. The checklist was completed by 480 outpatients with a cancer diagnosis. Sixty patients from each of eight primary tumour groups (lung, breast, gastrointestinal, gynaecological, urological, head and neck, brain and lymphoma) were recruited. The majority of patients (over 90%) rated 27 of the 29 checklist items, reporting a mean of 10 items as current problems. The influences of disease site and status, demographic factors and treatment on the number and type of symptoms and concerns reported were investigated. The highest number of symptoms and concerns and most severe problems were reported by patients with lung cancer, followed by those with brain tumours; the lowest by those with lymphoma and urological tumours. A high proportion of patients (83%) reported one or more items likely to benefit from SPC intervention. The results of this study suggest an extensive need for better symptom control in all cancer outpatients and in centres where SPC resources are limited, priority could be given to patients attending lung and brain tumour clinics.