Pleura empyema is a frequent disease with a high morbidity and a mortality rate of approximately 15%. Pleura empyema is characterized by the passage of three stages (I - III). The aim of treating the disease is to remove the infection and provide fully expansion of the lung. The initial treatment at the early stage of the disease (stage I) is simple drainage. In clinical practice, stages II and III are treated alike. Current standard treatment for these stages is drainage with ultrasound (ULS) -guided pigtail. Simultaneously with drainage, an intrapleural fibrinolyticum can be given. A potential better alternative is surgery in terms of Video Assisted Thoracoscopic Surgery (VATS). The theoretical advantage of early surgery is that patients undergo rapid, definitive treatment. Furthermore, surgery can ensure optimal drain placement. How best to treat these patients (drainage or surgery) is still under clinical evaluation and depends to a great extent on local clinical practice. It is only to a limited extent based on scientific evidence. The aim of this study is to determine if there is a difference in outcome in patients diagnosed with stage II and stage III empyema who either receive primary VATS surgery or ULS guided drainage and intrapleural therapy (fibrinolytic (altaplasm) with DNase (Pulmozyne ®)) The primary outcome is Hospitalization time and secondary outcomes is e.g. mortality, health related costs and quality of life. The present study can thus provide new and highly relevant knowledge as well as change the treatment of these patients, both nationally and internationally. It is planned that a total of 184 patients will be included in the project. The study takes place as a collaboration between all four thoracic surgical departments and the major pulmonary medicine departments in Denmark. In addition, the study has international collaborators/consultants who will provide counselling in connection with the study.