The current compression garment selection guide is targeted at the earliest clinical stages of chronic venous disease (CVD) and assumes a priori that application of a higher class of compression improves the calf muscle pump function, which is the major mechanism promoting venous return from the lower limb to the heart.Objective of the study: to evaluate the calf muscle pump function in patients with the early forms of CVD using different classes of compression garments.Material and methods: A total of 30 patients (45 lower limbs) with Class 1 CVD (CEAP classification) were enrolled in the study. The calf muscle pump function was evaluated during wearing compression garments using remote cableless photoplethysmography of Bodytronic measurement system (Bauerfeind, Germany) with automatic data processing. The investigators measured venous refilling time (T0) and pump capacity (V0) in patients without compression garments and also in those wearing classes 0, I and II compression garments (RAL standard, Venotrain micro, Bauerfiend socks). All indicators were measured three times with an interval of 30 minutes. The final values of T0 and V0 were calculated as average.Results and discussion: when the indicators were measured without compression and with zero compression, T0 was 26.7 ± 1.2 sec and 25.4 ± 1.1 sec (p = 0.56); V0 - 8.6 ± 0.7% and 8.0 ± 0.4% (p = 0.47). When the calf muscle pump function indicators were measured using class I compression garments, its performance was improved. Thus, T0 and V0 (p <0.01) increased significantly to 38.9 ± 2.1 sec and 12.9 ± 1.4%, respectively. When the calf muscle pump function indicators were measured using class II compression garments, T0 and V0 were 38.1 ± 1.6 sec and 8.1 ± 0.6%. Thus, the use of class I compression garments significantly improved the calf muscle pump function in patients with early manifestations of CVD. The higher level of compression (class II) did not improve T0 and worsened V0. This fact can be explained by excessive compression of the muscular venous sinuses caused by wearing class 2 compression garments, which, apparently, worsened the propulsive ability of the calf pump.Conclusion: the use of class I compression garments is optimal for the management of hemodynamic disorders in patients with early forms of chronic venous diseases (C1 according to CEAP). The higher class of compression does not improve the hemodynamic parameters of the calf muscle pump.