Exposure to phthalates is widespread because of their use in plastics, cosmetics, and other consumer products. Phthalate exposure has been associated with adverse respiratory outcomes in children. With urinary phthalate measures, we assessed the association between phthalate exposure and four pulmonary function parameters [forced vital capacity (FVC), forced expiratory volume at 1 sec (FEV1), peak expiratory flow (PEF), and maximum mid-expiratory flow] among the 240 adult Third National Health and Nutrition Examination Survey (NHANES III) participants with urinary phthalate data. Linear regression models controlled for race, age, age squared, standing height, body mass index, cumulative smoking, and current smoking. Monobutyl phthalate (MBP) was significantly associated with decrements in three measures of pulmonary function (FVC, FEV1, PEF) in males but not in females. For a change from the 25th to the 75th percentile in MBP level among men, FEV1 decreased 112 mL (SE = 51, p = 0.03). Monoethyl phthalate (MEP) was associated with lower FVC and FEV1 values in men. Monoethylhexyl phthalate (MEHP), the metabolite of the plasticizer commonly used in medical tubing, was not adversely associated with any of the pulmonary function parameters evaluated. Our results suggest that MBP and MEP, but not MEHP, may influence pulmonary function among adult males.