To evaluate cancer diagnosis disclosure in a cohort of cancer patients attending an outpatient oncology unit, a prospective observational study was performed. Three hundred twelve consecutive patients were accrued between January and June 2005. A questionnaire was given to each patient; the questions were very simple and related to demographics, residence, sex, educational background, employment status, time elapsed after diagnosis, treatment received, existence of relatives, and health insurance. All patients but one entered the study. There were 185 women and 127 men; 120 patients had breast cancer, 84 colorectal cancer, 34 lung cancer, 28 ovarian cancer, 34 gastric cancer, and 12 pancreatic cancer. Of the total 311 evaluable cancer patients, 171 (54.98%) were correctly informed; of the remaining 140 patients, 67 (21.54%) were not sure, and 73 (23.47%) thought their disease was not cancer. These data suggest that the majority of cancer patients attending our outpatient oncology unit are being correctly informed about their diagnosis. In our series the type of tumor had an important impact on diagnosis disclosure, while age and educational status did not.