Deep vein thrombosis is a chronic disease with a continuing risk of recurrence. In a patient with recurrence long term prognosis and treatment are significantly altered both carrying their own risks not only in the acute phase but mainly in the long term perspective. Thus, accurate diagnosis of recurrence is of utmost importance for the fate of the patient. Diagnosis of a first DVT episode is well established and follows an algorithm including clinical prediction rules, D-Dimer testing and compression ultrasound. Due to the previous episode the efficiency of all three elements is impaired in a patient with suspected recurrence. This opens up areas of uncertainty which have to be filled by individual clinical judgement. Guidelines reflect this difficulty by providing mainly weak recommendations based on sparse data. The present review summarizes what is known about the performance of tools for DVT diagnosis, discusses recent guidelines, and finally gives personally weighed recommendations how to deal with this peculiar diagnostic situation. In conclusion, it will turn out that the well accepted diagnostic algorithm for a first DVT may be applied as well if the lower efficiency is regarded. Compression ultrasound largely benefits from a baseline assessment at the end of the previous episode. The order of tests may be discussed according to local and regional attitudes.