A scoring system could be used in all situations where grading of deep leg vein thrombosis (DVT), including mapping of its distribution, is needed. It should also be used in epidemiological studies of DVT in further analysis of different risk groups suffering from DVT. Several scoring systems have been developed during the last three decades but have resulted in various complex and impractical systems. A scoring system should be easy to follow without any risk of misunderstanding and misinterpretation. All vein segments of importance should be defined and be possible to be included. This review describes and compares the scoring systems according to Marder et al., Arnesen et al., a subcommittee of venous disease and Björgell et al.