BACKGROUND: The need for training to equip primary care staff with the knowledge and skills to provide dietary advice to the public has been acknowledged. Little is known about the effectiveness of such training at improving the dietary counselling skills of multidisciplinary practice teams. AIM: To evaluate the effectiveness of a nutrition training programme, delivered to primary care teams by a dietitian. DESIGN OF STUDY: A paired-cluster randomised trial. SETTING: Twelve general practices in Sunderland, in the United Kingdom. METHOD: A nutrition training programme, aimed at improving the quality of dietary consultations, was developed and delivered to six primary care teams by a dietitian. Main outcome measures were patients' recall of seven key consulting behaviours. Data were collected from patients in intervention and control practices, pre- and post-intervention. Change in knowledge and attitude of practitioners was also measured. RESULTS: All 12 practices completed the trial. Data were collected from 251 patients pre-intervention and 228 patients post-intervention. Of the seven consulting behaviours targeted in the training, only the proportion of consultations where written information (diet sheets) was provided to patients was significantly higher (13% higher, 95% confidence interval [CI = 4 to 21, P = 0.004) in the intervention practices post-training. Some evidence of improved practitioner knowledge and attitude was detected. CONCLUSION: This evaluation of a nutrition training intervention detected only a limited impact on the behaviour, knowledge, and attitudes of primary care practitioners in dietary consultations.