Deep venous thrombosis (DVT) is a common condition. The diagnosis is a clinical challenge. If left untreated it can cause pulmonary embolism and death. During the last decades non-invasive and more cost-effective diagnostic strategies have been developed. The National Board of Health and Welfare in Sweden published new guidelines for diagnosis and treatment of DVT in 2004. In accordance with these, the Department of Internal Medicine, University Hospital of Örebro and the Primary healthcare in the County of Örebro developed local guidelines for venous thromboembolism. This is a retrospective quality-control study. The results of all ultrasonographic exams of patients at the Medical Emergency Department and from the GP’s in Örebro 2003-2005 were examined. The aim of the study was to evaluate the adherence to the new guidelines and to find out if the number of flebographic exams decreased. Furthermore, we wanted to see if the incidence of DVT did decrease as a sign of less sensitivity of the new strategy. 1923 ultrasonographic exams and 172 medical records were studied. Conlusion: The new guidelines have lead to fewer flebographic exams and higher proportion of positive flebographies. The adherence to the guidelines is good, and considered reliable.