Abstract Background The education and training of health care practitioners has undergone recent reform, and indicate that curricula should place emphasis on the development of clinical skills and attitude. The purpose of this study was two-fold: to define the key skills necessary for a competent dietetic student practitioner and to devise a reliable assessment tool to measure and track performance in these key skill areas throughout the period of clinical placement. Methods Key clinical skills were identified by a concensus group of experienced dietitians and academic practitioners. An assessment tool was then developed to measure these attributes in 43 students undertaking clinical placement at a number of training centres in Scotland. Development of skills was tracked for the entire duration of placements using the novel assessment tool. The assessment tool used a visual analogue scale (VAS) as the measuring score. Results A high level of skill attainment was equated with high VAS scores. Performance in three of the four key skills (written skills: r = 0.762, P ≤ 0.001; interviewing skills: r = 0.697, P < 0.001; and dietary assessment technique: r = 0.697, P ≤ 0.001) showed impressive correlation co-efficients, indicating a striking and significant positive correlation with the length of training. A high skill performance level attainment was achieved by week 16/17 of training. Conclusion The authors are confident that the assessment tool is valid and reliable and measures skill performance objectively. A high level of skill attainment was observed in most students by about the mid-point in training: this allows the student to consolidate these skills in the latter stages of training which is in keeping with educational and practice philosophy of placement learning outcomes.