One hundred and sixteen mature students following advanced courses in education anonymously completed Musgrove's scale assessing their attitudes towards behaviour modification and its use in educational settings. Their overall mean score suggested a general ambivalence of attitude; this sample, as a whole, being neither strongly pro nor anti behaviour modification. Neither sex, age, number of years teaching experience nor age or type of children taught were significantly related to attitude score, but there was evidence to suggest a strong positive relationship between prior knowledge of behaviour modification by study or practical experience and attitude score. This finding that the more teachers knew about behaviour modification the more positive were their attitudes was also supported by a retest study. Forty-four of the original sample were retested after completing a course in behaviour modification, resulting in significantly more positive attitude scores. Factor analyses provided support for Musgrove's original findings.