Objective: To evaluate the effect of a needs-based, nutrition education leaflet on nutritional knowledge. Design: Comparison of nutritional knowledge levels before and after exposure to a nutrition education leaflet. Setting: A regional colorectal out-patient clinic in Edinburgh. Method: A nutrition education leaflet, based on an earlier needs-assessment, was used in the study. Patients attending an out-patient clinic with colorectal symptoms were invited to participate. Nutritional knowledge was determined using a validated questionnaire in a semi-structured interview. In Group A, nutritional knowledge was determined at baseline and after exposure to the leaflet. In Group B, nutritional knowledge was determined after exposure to the leaflet and again one month later. Results: In Group A (n = 35), there was a significant increase in awareness of the "5 fruit and vegetables a day" (46 per cent v 91 per cent, p less than 0.001 ) and "what constitutes a portion of fruit and vegetable" messages (38 per cent v 71 per cent, p less than 0.05), compared with baseline. In Group B (n = 52), knowledge levels were maintained after one month, and during this time, 12 (23 per cent) subjects reported an increase in their fruit and vegetable intake. Conclusion: Targeted nutrition education significantly increased levels of nutritional knowledge, which was sustained one month later. Nearly a quarter of the cohort reported improvements in their dietary intake, which suggests that this method of nutrition education may be particularly cost-effective in facilitating dietary change. (Contains 5 tables.)