The diagnosis and treatment of granulomatous lung diseases is challenging. This article describes two of these entities: (1) eosinophilic vasculitis with polyangiitis which is clinically characterized as a combination of bronchial asthma and eosinophilic granulomatous vasculitis. Antoneutrophil cytoplasmic antibodies are present in approximately 40 % of patients. Treatment with steroids is sufficient in patients with isolated pulmonary manifestation but extrapulmonary manifestations, e.g. heart, central nervous system (CNS), kidneys and gastrointestinal tract warrant combined immunosuppression with prednisolone and cyclophosphamide. (2) In Germany tuberculosis is an orphan disease with an incidence of 5.3/100,000 in the year 2011. Prolonged cough, night sweats and weight loss should be considered suspicious of tuberculosis. Microbiological diagnosis has been improved by gene and PCR technology. The traditional Mendel-Mantoux skin test has widely been replaced by the interferon gamma release assay (IGRA). Standard treatment of non-resistant mycobacterium tuberculosis is based on a combination of isonizide, rifampicine, pyrazinamide and ethambutol for 2 months followed by 4 months of isoniazide plus rifampicine. Therapy resistant, multiple drug resistant (MDR) and extensively drug resistant (XDR) tuberculosis bacteria should be treated by experienced specialists.