This case is reported primarily owing to the large size of the diverticulum, and secondly owing to the unusual association of a carcinoma in its wall. The patient, who was a man aged 59, was admitted to St. Bartholomew's Hospital under care of Mr. Capps, complaining of a swelling in the neck and dysphagia. He gave the following history:— In 1902 he had some difficulty in swallowing at the end of his meals, with the appearance of a swelling in the left side of the neck and some discomfort. Regurgitation of a quantity of semi-digested food caused relief and made the act of swallowing easier. This had occurred on and off for many years. In April 1932 he complained of some loss of weight and brought up about three ounces of blood. In May 1932 he had a complete obstruction to the passage of all food and was admitted to St. Bartholomew's Hospital with a diagnosis of pharyngeal pouch. A gastrostomy was performed on May 11, 1932.