OBJECTIVE: An exploratory study has been carried out to examine decision-making role preferences and information needs for a sample of people with colorectal cancer (n=48). The work replicated a larger study carried out for women with breast cancer (n=150), and this paper compares and contrasts findings for both disease groups. DESIGN: A cross-sectional design was employed, involving structured interviews. The main variables investigated were decision-making preference (using a decisional role preference card sort), perceived decisional role and information need (using an information needs questionnaire). RESULTS: The majority (78%) of the colorectal cancer patients preferred to play a passive role in decision making, in contrast to 52% of women with breast cancer in previous work. Eighty per cent of the colorectal sample and 61% of the women with breast cancer perceived that the doctor had made treatment decisions. Priority information needs for both groups related to cure, spread of disease and treatment options. CONCLUSIONS: The two most striking findings from the comparison between the two disease groups relate to the differences in decision-making role preferences and the similarities in information needs. The process of involving people with colorectal cancer in treatment decision making warrants further investigation. The similarity in information needs of the two disease groups has implications for health care professionals providing information to people with cancer.