A scale for assessing information needs of cancer patients was constructed and validated. Two studies were conducted. Study 1 was designed to test the factor structure of the measurement instrument. A total of 498 patients with breast cancer and Hodgkin disease were interviewed. In study 2, 133 patients with head and neck cancer were measured just before treatment as well as 6, 13 and 52 weeks after treatment. Study 2 aimed to confirm the factor structure established in study 1, and to test for construct validity in a new population, the psychometric properties of the information needs scales, and the scales' sensitivity to change. In study 1 a two-factor structure (an action and a disease-oriented scale) including 17 items was revealed. The second study confirmed the factor structure from study 1. As hypothesized, greater information needs related to higher levels of state-anxiety, more depression, and more psychological complaints. Although, correlations over time per information need scale indicate some stability of scores, findings suggested that the need for information about disease and treatment is less stable over time than need for information about access to help and solutions. Further validation of the instrument is required.