This study was initiated by senior scientific officer Elisabeth Hegstad and professor Arne R. Rosseland at Aker Hospital in 2002. Since 1999 Rosseland has secured video documentation of laparoscopic cholecystectomies at Ski Hospital, with the intention to register all perioperative events. We wanted to determine in which frequencies and what anatomical positions the events occur. The data was first analyzed in the summer of 2003, and presented at The Annual Meeting of The Norwegian Surgical Society that year. The second analysis was conducted in the winter of 2004 and its results were presented at The XXXVI Nordic Meeting of Gastroenterology. Material and Method The first analysis was based on data from 201 operations and the second analysis from 209 operations. In both analyses seven operations had to be excluded due to two black videotapes. The events were grouped in the following categories; bleeding, perforation of the gallbladder, perforation to the cystic duct, bile duct injury, lesion to the liver, lesion to the abdominal wall, lesion to the intestine and loss of bile of gallbladder stones into the peritoneal cavity. Details such as anatomical position and type of instrument causing the event were also registered. Results The first analysis generated two presentations. The first, a video presentation describing the definition we used for bleedings. The second, an oral presentation of frequencies of events and the instruments involved. In the second analysis we examined which anatomical position the event occurred in. Status Following these presentations the study has entered a new phase. During the second half of 2004 we started to register data from the patients’ records. Now, we want to ascertain whether there is any difference in patient outcome between the group of patients who experienced events during the operation and those patients who experienced no events. A fellow student has written an article on the subject ”quality of the dictated operative note”, using the same data.