PURPOSE To understand the preferences and attitudes of patients and family caregivers on disclosure of cancer diagnosis and prognosis in an Indian setting. METHODS Overall, 250 adult patients with cancer and 250 family caregivers attending the outpatients of a tertiary cancer hospital for the first time were recruited purposively. The mean ages of patients and caregivers were 49.9 years (range, 23-80 years) and 37.9 years (range, 19-67 years), respectively. Separately, they completed prevalidated, close-ended preference questions and were interviewed for open-ended attitude questions. RESULTS A total of 250 adult patients (response rate, 47.17% overall, 73.2% in men, and 26.8% in women) and 250 family caregivers (response rate, 40.65% overall, 84.0% in men, and 16.0% in women) participated. Significant differences were observed in the preference to full disclosure of the name of illness between patients (81.2%) and caregivers (34.0%) and with the expected length of survival between patients (72.8%) and caregivers (8.8%; P < .001). The patients felt that knowing a diagnosis and prognosis may help them be prepared, plan additional treatment, anticipate complications, and plan for future and family. The caregivers felt that patients knowing a diagnosis and prognosis may negatively affect the future course of illness and cause patients to experience stress, depression, loss of hope, and confidence. CONCLUSION Patients with cancer preferred full disclosure of their diagnoses and prognoses, whereas the family caregivers preferred nondisclosure of the same to their patients. This novel information obtained through a large study with varied participants from different parts of the country will help formulate communication strategies for cancer care.