To define whether the levels of immunoglobulins and albumin in bronchoalveolar lavage (BAL) fluid are related to the intensity of sarcoidosis alveolitis, 49 patients affected with pulmonary sarcoidosis were studied. To distinguish between high- and low-intensity alveolitis, two parameters were used: the percentage of T lymphocytes and the CD4+/CD8+ ratio in BAL fluid. The results showed an increase of albumin and of the IgG/albumin ratio (p less than 0.05) in patients with high-intensity alveolitis as assessed by both criteria. Moreover, an increase (p less than 0.05) of albumin concentration related to T lymphocyte alveolitis was found. We conclude that: albumin is a reliable index of inflammation; the increase of the IgG/albumin ratio is the expression of local production of IgG as well as of inflammation; the evaluation of albumin and of the IgG/albumin ratio should be useful because they both correlate with the intensity of the alveolitis: the former express inflammatory damage and the latter, immunological activity.