Objective: The aim of this study was to evaluate information requests and disclosure in cancer patients. In addition, the reasons of dissatisfaction with information disclosure were discussed. Material and Methods: The research was conducted among patients in the Medical Oncology Department of Uludag University Research and Practice Hospital in Bursa between June and September 2005. Data were collected during face-to-face interviews run by the main author using a questionnaire. Results: The study group consisted of 104 patients. Most patients (78.8%) were aware of their diagnoses and 81.7% wanted full information about their diagnosis and treatment. The information disclosure was mostly about "how the treatment was going to be done" (78.8%) and "what the side effects were" (69.2%). There was a satisfaction rate of 67% with the information disclosure and reasons for dissatisfaction included incomplete information (43.3%), the use of medical terminology during the information disclosure (33.3%) and that the physicians could not allocate adequate time for them (23.4%). When compared to the patients who were not informed by the doctors, the rate of satisfaction in informed patients and their rate of asking questions about what they wanted to know were higher (p<0.05). There were no statistically significant differences between the demographic characteristics and information requests. Conclusion: Information disclosure about cancer diagnosis and treatment is not sufficient when the expectations of patients are considered. Even though consent is obtained from all, it is clear that patients may not find the information sufficient and therefore they cannot fully participate in the medical processes.