Standardized classifications and scores are fundamental for clear terminology in medicine and absolutely necessary in order to compare studies from different groups or institutions. We recommend a four-level classification to typify acute superficial thrombophlebitis (STP). All the different forms of acute STP can be differentiated into these four types: side branch STP (type 1), segmental trunk STP (type 2), ascending trunk STP (type 3), and trunk STP reaching the junction (type 4). Associated codes make it possible to describe the extent of the thrombophlebitis and the location of the affected venous trunks (a: calf, b: thigh, c: including calf and thigh, x: associated with deep venous thrombosis, M: great saphenous vein, P: small saphenous vein).