The subject of chronic cholecystitis will be dealt with in two parts: Part I. A series of 247 consecutive cases operated on for chronic cholecystitis, with or without stones, has been analysed. These cases are viewed from various angles, and in particular an attempt is made to correlate the findings at operation with etiological factors observed, symptoms and radiological findings. These cases will be dealt with under the following headings:- Sex incidence • age incidence • Age and sex incidence • Pathological findings at operation • Etiology • Symptomatology • Radiological findings • Operative mortality • Summary Part II. This consists of a follow-up of patients after operation. All the 247 cases were operated on from one to ten years previously, and an attempt was made to get into touch with each of these cases. This was successful in 162 cases. An attempt is made in these cases to assess the degree of success which has followed operation. In particular an attempt is made to show which types of case were most benefitted by operation by correlating the operation results with the findings at operation. These cases will be dealt with under the following headings:- Method of follow-up • Classification of results • Object of follow-up • Results in chronic cholecystitis with or without stones • Results in different groups (1) Multiple mixed stones (2) Single cholesterol stones (3.) Single cholesterol plus multiple mixed stones (4) Pigment stones (5) Stoneless gall- bladder (6) Cholesterosis • Symptoms which persist after operation • Summary.