This study was designed to determine the frequency of recidivism (patients using a service more than once for the same or different disease episodes) in a helicopter emergency service, with the premise that high levels of recidivism may constitute grounds for improving quality of care or patient education programs. A retrospective chart review was performed on records from June 1985 to September 1990. Patients were included if they required helicopter transport on more than one occasion for either different disease episodes (true recidivists) or for multiple transports during a single hospital admission. Twenty-one (0.6%) of the 3,543 patients transported were true recidivists and 20 (0.6%) patients required secondary transport during the same admission. Of the latter group, 17 secondary transports were within 24 hours of admission. This study showed that recidivism in this helicopter emergency service is low. Patients who were air transported more than once for the same illness or injury within a 24-hour period occurred in less than 1% of transports, well within the helicopter program's pre-established less than 2% threshold.