The aim of this study was to form and test a model of the antecedents and possible moderators of the use of clinical guidelines among healthcare professionals. A postal questionnaire survey of all workers in six health centres around Finland. was carried out in April 1996. The health centres were selected to represent all different areas of Finland. A total of 748 (65.5%) of the healthcare workers completed and returned the questionnaire. Of the respondents 95% were women, 16% physicians or dentists, 31% registered nurses, and 27% practical nurses. It was hypothesized that besides positive attitudes towards guidelines, job characteristics and team climate affect the use of guidelines. Three alternative models of possible main and moderating effects of attitudes, job characteristics, and team climate were formed and tested. These models were tested using hierarchical regression analysis and structural equation modelling (LISREL8). All of the hypothesized main effects and the moderating effect of job characteristics between attitudes towards and the use of guidelines were supported. According to our results important factors behind the general positive or negative attitudes towards guidelines are the usefulness, reliability, practicality, and availability of the guidelines. Also, the overall individual, team, and organizational competence to follow the procedures recommended, seemed to be vital. Moreover, those whose job motivation potential was high were more ready to use clinical guidelines even when their attitudes towards guidelines were the same.