Three hundred and forty-five questionnaires containing the knowledge and attitude scale for ECT devised by Janicak et al. (1985 ) were distributed to mental health nurses working in Wales, the data were collected from the 167 returned. Limitations in the reliability of the instrument with respect to the degree of internal consistency were found, this suggested that the knowledge statements used were inconsistent in providing a reliable measure of respondents knowledge of ECT. Findings suggested that a higher level of knowledge appeared to be associated with the length of experience of the nurse and their area of clinical practice. In addition, there were substantial variations in actual knowledge, particularly with regard to cognitive side-effects with ECT. Attitudes to ECT in this study were significantly related to the place in which the nurse was practising and the degree of contact the nurse had with patients receiving the treatment. Greater knowledge scores were obtained by those nurses who indicated a more positive response towards ECT. The conclusions suggest that knowledge of ECT required improvement in many cases, and this has implications for nurse education. A relationship between knowledge and attitudes appears to exist in this study, however, such a relationship would need to be tested further in future research.