This study investigates the factors which influence the reported use of a smoking cessation interventions in antenatal clinics. Midwives and doctors in 20 hospital antenatal clinics (n = 203) completed a survey designed to measure their perceptions, knowledge and use of brief interventions for smoking. Measures for hospital structure and work climate were also obtained. The aims of the study are: to describe the smoking intervention practice of antenatal clinic staff and to ascertain the organizational and practitioner variables which predict clinician use of smoking interventions. The results indicate that the majority of antenatal clinic staff do not use the most effective forms of brief interventions for smoking. The presence of specific procedures and training in smoking cessation intervention appear to be the most important predictors of reported smoking intervention in hospital antenatal clinics.