Truth Telling has been found as one of the most important issues in physician patient communication. Therefore all of the physicians are concerned with this matter in some way. Disclosure or reticence of the truth has also caused ethical or legal problems. So correct approach to this issue is very important. Truth– telling is more important especially in some diseases such as cancer because it has a meaning as same as death in many cultures. It seems stage of cancer, social culture, socioeconomic condition, intelligence, education and some other factors affect patients, view and duration of practice stage of disease and some other factors influence physicians, opinion the main goal of this plan is to determine the attitude of patients and physicians about truth telling to cancer patients.This study is a descriptive one that has been performed in Omid hospital in Isfahan. The bulk sample was considered 50 physicians and 150 patients. The sampling method was non probability for physicians and non-probability (sequentional) for patients. The tool of gathering the data were two standardized questioner’s (every include 22 questions) asking about attitude. Gathering data was analyzed by SPSS software.All of the questionnaires were analyzed. About truth telling to early stage cancer patient %88 of patients and %90 physicians were agree and %78 patients and %72 physicians were agree with truth telling to terminal stage cancer patient. Both of physicians and patient were agree with frankness in telling the diagnosis, no effect of patient socioeconomic condition on truth telling and telling the truth immediately after diagnosis. In both group view doctor is the best person for telling the cancer diagnosis. The best place in patients, view is doctor office and in physicians, view is a quiet and undisturbed room. The majority of idea in both groups was giving the complete information to cancer patients about diagnosis, prognosis, treatment and side-effects of treatment.Discussion: Noticing the obtained results in our society culture, the majority of patients regardless of age, sex, marring state level of education, job condition and incoming, and the majority of physicians regardless of age, sex, marring state, having relative with cancer and medical experience had positive attitude about truth telling to patients in different stages of cancer. So it seems it is one of the essentials to tell the truth based on a correct method.