Pulmonary colonization with Burkholderia (Pseudomonas) cepacia in cystic fibrosis (CF) patients has been associated with high morbidity and mortality. The aim of this study was to investigate whether the dentist and the dental surgery environment become contaminated during treatment of CF patients colonized with B. cepacia. Extensive environmental sampling was carried out during aerosol-generating treatment sessions on four CF patients whose sputum was persistently colonized with B. cepacia. Samples of surgery air, and of water from the air-turbine, three-in-one syringe and their supply-lines, were tested before and after an aerosol-generating treatment session with each patient. Settle plates were placed on the bracket table and work-surfaces, and within the portable suction unit's exhaust housing unit during treatment, and swabs were obtained from various items of dental equipment at the end of treatment. Swabs of the buccal mucosa were obtained from each patient before treatment, and from the dentist before and after treatment. B. cepacia was isolated from the swabs of three of the patients, but not from those taken from the dentist or from any of the environmental samples. The results suggest that CF patients colonized with B. cepacia appear to constitute a low risk for environmental contamination and are unlikely to be an important means of transmission between CF patients.