Thoracoscopy is useful for the diagnosis and treatment of many conditions in veterinary patients. It decreases patient morbidity and improves visualization and lighting of structures within the thorax due to the magnification and lighting adjacent to the structures evaluated. The complications of thoracoscopy are described, as is the need for converting to an open thoracotomy. Complications and the need for conversion depend on the patient and the procedure performed. Procedural complications are not discussed unless they specifically relate to thoracoscopy. As confidence is gained with thoracoscopy, the need for conversion may decrease over time. However, conversions may be required more often as the degree of difficulty of thoracoscopic procedures increases.