The study presents our experience with video-assisted thoracoscopy and video-assisted thoracoscopic surgery (VATS) at the Dept. of Thoracic and Cardiovascular Surgery at Odense University Hospital. All VATS-procedures performed in the period 1/1 1993-30/9 1994 were prospectively registered. Sixty-seven procedures were undertaken on 63 patients with a median age of 35 years (range, 13-75 years). Twenty diagnostic and 47 combined diagnostic and therapeutic procedures were performed. The indications were spontaneous pneumothorax, pleural changes, diffuse interstitial lung disease, Raynaud's disease, localized lung lesion, and abnormal chest X-ray in patients with previous extrathoracic malignancy. In patients with pneumothorax, the most frequent procedures were pleurodesis with fibrin glue sealant, wedge resection with endostapler, and pleural abrasion. In the remaining groups, the most frequent procedures were pleural biopsy, wedge resection of lung parenchyma, and thoracic sympathectomy. The median time consumption during the surgical part of the VATS-procedures was 50 minutes (15-130 min.), and median hospitalization time after VATS was three days (1-10). Drains were left for more than two days after 13 procedures (22%), most often due to air leakage or persisting pneumothorax. Four VATS-procedures were converted to thoracotomy, and three had thoracotomy at a later stage during hospitalization. All thoracotomies were related to preexisting disease. No major procedure-related complications occurred. A diagnosis was achieved in every case where VATS was aimed at being purely diagnostic. Two patients had sympathectomy with good results. We conclude that VATS seems of advantage for diagnosis and therapy in many cases of benign intrathoracic disease. In addition, a histological diagnosis can be achieved and operability assessed in many cases of intrathoracic malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)