The aim of this study was to assess the effectiveness of four training workshops at the inception of a programme to cascade critical appraisal skills training throughout Scotland. Data were collected from all participants and organizers at four commissioned critical appraisal skills training workshops in Scotland. The collection of data involved three components: a survey of workshop participants before and after each workshop to determine knowledge of the principles of clinical effectiveness; semi-structured interviews with organizers before, during and after the programme of commissioned workshops to assess views on the workshops; and a postal survey to determine involvement in critical appraisal activities following the initial workshops. The main outcome measures were 'change in knowledge' and subsequent involvement in teaching. An average of 41 people attended each workshop. Participants improved their scores on understanding of clinical effectiveness. Not all of the improvement can be ascribed to the workshops, however, because control item scores also improved, albeit to a lesser extent. The workshops were perceived as an acceptable way of acquiring critical appraisal skills, but doubts were expressed about whether participants would be able to roll out the programme on their own. Of the 32 (42%) attendees who were involved in CASP-style workshops after the initial workshops, 26 (34%) providing aspects of teaching, and a further six (8%) were participants. The evaluation of the CASP workshop technique suggests that it does improve knowledge of clinical effectiveness, but concerns remain about the viability and reliability of this approach as it rolls out training within Scotland.