A case of Pulmonary Alveolar Proteinosis (PAP), in association with tuberculosis, is described in a 35-year-old diabetic patient. Lung biopsy showed an intra-alveolar accumulation of PAS-positive material, and multifocal granulomas compatible with tuberculosis. The bronchoalveolar culture was positive for Mycobacterium tuberculosis. PAP results from an imbalance of the mechanisms that regulate the homeostasis of the surfactant, where specific proteins are involved, especially SP-A and SP-D, the cytokines, IL-10 and GM-CSF, in addition to alveolar macrophages and type-II pneumocytes. Chemotaxis and phagocytic capacity are reduced. PAP and diabetes share several immunological disfunctions that may increase the risk for tuberculosis. Although there are no controlled studies, the diagnosis of PAP in diabetic patients with tuberculosis must be considered.