To assess and compare health information wanted and obtained from doctors/nurses by Chinese cancer patients and family caregivers. (1) What are the instrument's psychometrics in Chinese cancer patients and family caregivers? (2) How might Chinese cancer patients and family caregivers differ in the amount of different types of health information they want to have? and (3) How might Chinese cancer patients and family caregivers differ in the amount of different types of information they were able to obtain from doctors/nurses? This was a cross-sectional study using a paper-pen questionnaire. A total of 198 participants (79 cancer patients; 119 family caregivers) from a general hospital in Sichuan, China completed the instrument in March 2014. The instrument has excellent reliability and validity. Participants wanted to have a wide range of health information, including but not limited to information about diagnosis or treatment. Across all types of information, participants obtained from doctors/nurses significantly less than what they wanted. The discrepancy between information wanted and obtained varied across different types of information. The discrepancy was largest for information about complementary and alternative medicine (CAM) and psychosocial aspects and smallest for information about diagnosis and self-care. Patients and caregivers did not differ in the amount of different types of information they wanted or obtained from medical professionals. There is a great need for providing more information to both patients and their families, particularly information about CAM and psychosocial aspects.