To investigate the effects of intentional hydrocarbon inhalation on lung function, a preliminary study involving ten spray paint abusers was conducted. Mean duration of the inhalation was 34.9 months; mean frequency was 3.2 times per week. Pulmonary function testing (PFT) consisted of flow studies, lung volumes, single-breath carbon monoxide diffusing capacity (Dsb), airway resistance and airway conductance. An exercise provocation was followed by repetition of the PFT, except for Dsb. Our results revealed an obstructive ventilatory pattern in 90 percent of the subjects. In seven patients, there was a significant increase of airway resistance prior to exercise. In five of the ten patients, exercise provocation produced an increase in residual volume. Five of six subjects receiving a trial of a bronchodilator had significant improvement of obstruction. These findings suggest that intentional inhalation of spray paint may produce abnormalities in pulmonary function. These abnormalities may improve after use of a bronchodilator.