Much of the argument for or against diagnosis of distal deep vain thrombosis (DVT) depends on the extra effort that has to be spent on it. This review presents the data on ultrasound of paired calf veins and calf muscle veins (distal ultrasound) in terms of protocols, feasibility, reliability and expected findings. In summary, provided there is adequate and anatomically sound training of sonographers, distal ultrasound is a valid, 4-minute procedure, which can easily be added to the examination of proximal veins. The second part of the review refers to the pathophysiology of ascending DVT, which is the most common type. Adequate patient care in terms of benefit, harm and cost includes a single non-invasive examination followed by risk adopted treatment allocation. This concept ideally should be valid for any type of DVT. The data extending this concept to distal DVT can only be derived from studies that look closely at this entity (i.e. in fact diagnose distal DVT). Even before these data are available, diagnosing distal DVT at least doubles the number of symptomatic patients in which signs and symptoms can be ascribed to a definitive diagnosis, which in itself is a benefit for patient care.