Adenovirus in bronchoalveolar lavage fluid samples from 50 patients without adenovirus-related illness was quantified. In 49 patients, adenovirus was found (median load, 3.3 x 10(3) copies/microg of DNA). The adenovirus load was inversely related to lymphocyte count (Pearson correlation coefficient r = -0.311; P = .03) and was significantly greater in immunosuppressed patients than in immunocompetent patients (5.1 x 10(3) vs. 2.0 x 10(3) copies/microg of DNA; P = .028).