Introduction. To reach health care decisions that are satisfactory to both health care professionals and patients, it is important to understand cancer patients' information needs to facilitate delivery of care and to design educational programmes. The objective in the present study is to assess instruments designed to gather data on cancer patients' information needs. Method. To conduct the review, the present research identified fifteen instruments for measuring cancer patients' information needs. An outcome measures rating tool developed at McMaster University was used to assess the instruments on scale construction, level of measurement, reliability, validity and overall utility. Analysis. Data were extracted on each instrument in accordance with the rating system to ascertain attributes being measured, time to complete the assessment, scale construction, standardisation, reliability, content validity, construct validity and criterion validity. No synthesis of the abstracted data was attempted in the present review as the purpose was to inform health care professionals and researchers about the nature and characteristics of applicable measurement tools. Results. Several instruments were rated excellent in content validity; however, construct and criterion validity were poor. Content validity was based on literature, experts, clinical professionals, patients and family members. Different methods of testing reliability indicated adequate to excellent reliability for most instruments. Some instruments could not be assessed due to lack of data on reliability and/or validity testing. Conclusions. The Toronto informational needs questionnaire - breast cancer, its adaptation by Dale et al., and Thurstone scaling of information needs are rated highest as reliable and valid instruments, which can be used in developing and testing instruments further in different cancer patient populations.