Objective We aimed to determine the overall profile of patients in a psycho-oncology clinic and the differences in their characteristics according to the cancer site. Methods The charts of 740 patients aged under 81 years were reviewed. The data from 586 completed questionnaires were subjected to multiple comparison analyses using one-way analysis of variance to examine the demographic and clinical differences according to the cancer site. Results Most (n=532, 71.9%) patients were referred. Most new patients (n=426, 96.6%) received a psychiatric diagnosis; the most common diagnosis was depressive disorder (n=234, 31.6%). Likewise, depressive disorder accounted for the majority of diagnoses in all groups except for the digestive system cancer group in which sleep-wake disorder was the most prevalent. The female genital cancer group showed a higher level of anxiety symptoms than other groups, except for breast and haematolymphoid cancer groups, and psychological distress than all other groups. Conclusion There appear to be delays in the referral of cancer patients seeking psychiatric help to a psycho-oncology clinic. Along with tailoring approaches by cancer site, thorough evaluation and appropriate management of sleep-wake and anxiety symptoms are important for digestive system and female genital cancer patients, respectively.