An increased risk for obstructive sleep apnea (OSA) has been suggested for World Trade Center (WTC)-exposed workers. The authors reviewed the results from nocturnal polysomnograms (PSGs), to investigate diagnostic differences between WTC-exposed and -unexposed subjects. Six hundred fifty-six nocturnal PSGs performed at our sleep center were reviewed, 272 of them in former WTC workers. Seven diagnostic categories were compared between the 2 groups by bivariate and logistic regression analyses. The WTC group had a significantly higher predominance of the male gender, but slightly lower body mass index (BMI). There was no significant difference in the distribution of PSG diagnoses between the 2 groups in unadjusted (p = .56) or adjusted (p = .49) analyses. The authors did not identify a significant difference in PSG diagnoses between the WTC-exposed and -unexposed subjects. OSA was significantly associated with age, BMI, and gender in this patient population.