The authors observed 68 drug addict in-patients, who received treatment for the pneumonia at the Primorski Regional Clinical Hospital and Vladivostok Municipal Clinical Hospital No. 1. The article details the specific features of the pneumonia of these in-patients. It was distinguished the 3 groups of hospital patients with the following characteristic features: patients with the respiratory distress syndrome of the adults; patients with the primary infective endocarditis mainly with the damage of respiratory (right) heart; patients with non-specific pneumonia. The peculiarities of the clinical process with the X-Ray pictures of the disease were also presented. The article identifies the acute beginning of the disease; the strongly pronounced intoxication syndrome; the usual cases of the late going to hospital of those patients; the extensiveness of the damage; the occurrence of the following complications at the early stage: pulmonary destruction, exudative pleurisy, empyema; the long period of the disease process; the development of the extensive pulmonary fibrosis. It was identified the 33.7% lethality for these groups of in-patients, while the average lethality of the in patients treated for pneumonia was 3.3% for the same period of time. The complicated pneumonia process of young patients with the infective endocarditis with damages of respiratory (right) hearts let us suppose their drug addiction.