The article presents results of the reliability study of controlled groups of vehicles possessed by two road transport enterprises working in the international transport sector (truck tractors – VOLVO FH 1242Т – 50 unit and MERCEDES-BENZ 1844 ACTROS LS -100 units, semi-trailers SCHMITZ, KRONE and KÖGEL – 50 units from each of the semi-trailers company). Possibilities for reliability increasing and reduction of the maintenance and repair cost are defined. The results of the reliability evaluation of vehicles during three years of operation with a different annual run (from brand new up to 440·103 km, including warranty period) are presented. Based on the conducted studies of failures and details malfunctions, units and systems of the vehicles, the average operating time to failure or occurrence of malfunctioning, the probability of failure-free operation, and the time spent on repairs were determined. Asymmetric graphs of working capacity disturbance were obtained, which allowed determining the level of const uction design perfection, the technological accuracy of equipment assembly and the quality of fastening works. The inadequate adaptability to operate on the roads of the CIS was reflected by symmetric distribution laws. The least reliable aggregate and assembly elements were identified.