OBJECTIVE: To reduce the risk of pathogen transmission between patients with cystic fibrosis (CF) and decrease the rate of acquisition of new CF pathogens in our patients. DESIGN: Using the Model for Improvement, we developed a new process for infection prevention and control in our outpatient CF clinics. SETTING: Paediatric CF programme at Ann & Robert H. Lurie Children's Hospital of Chicago; approximately 180 paediatric patients aged birth to 21 years. PARTICIPANTS: All paediatric patients enrolled in the Cystic Fibrosis Foundation Patient Data Registry at this institution. INTERVENTIONS: Implemented contact precautions with all patients, regardless of respiratory tract culture results. MEASUREMENT: Respiratory tract culture rates of specific pathogens by quarter were compared prior to and after implementation. RESULTS: Our percentage of patients with a positive respiratory tract culture for Pseudomonas aeruginosa dropped from 30% to 21% (p<0.0001) and for methicillin-resistant Staphylococcus aureus (MRSA) dropped from 10.8% to 8.7% (p=0.008). CONCLUSIONS: Use of contact precautions by all care providers, for all patients, regardless of respiratory tract culture results resulted in decreased P aeruginosa and MRSA infection rates.