Chronic chest pain is a common complication following thoracotomy, which is generally attributed to intercostal neuritis or neuralgia. Response to medical treatment is poor. We report a case of persistent chest pain following open lung biopsy, which was found to result from lung herniation, a rare, but surgically correctable complication of thoracotomy. Since lung herniation may be easily overlooked, this disorder should be considered more often in the differential diagnosis of persistent postthoracotomy chest pain.