Pneumothorax is a condition in which air from lungs or outside of the body enters pleural cavity and causes lung to colapse. According to the cause of occurrence, pneumothorax can be spontaneous, traumatic and iatrogenic. By duration, it can be acute or chronic, and by size: partial and complete. Primary spontaneous pneumothorax is the one that mostly occurs in healthy, young, tall and thin man. Secundary spontaneous pneumothorax is usually a complication of underlying lung disease. Traumatic pneumothorax is the consequence of chest trauma. Iatrogenic pneumothorax occurs as complication of medical interventions. Chest pain and dyspnea are the usual predominant presenting features. The diagnosis is based on a clinical presentation, anamnesis and physical examination and radiological examinations. Diagnosis can be confirmed in the majority of cases with an upright posteroanterior chest radiograph. The treatment of pneumothorax depends of type and size of pneumothorax, general condition of patient, patient's profession and on the personal preference of the doctor. Terapeutic options are: observation, aspiration (thoracocenthesis and chest tube drainage) and surgical treatment (toracotomy and VATS). The goal of treatment is complete lung reexpansion and prevention of recurrence.