This study analyzes failures of dump trucks in open pit mines depending on the season and dump truck service life during placer mining in the permafrost zone. It i s found that more than half of failures are the faults of suspension, engine and drive axle. It is determined that the number of failures of dump trucks increases in the warm season (May–Sep tember) and with extension of service life of dump trucks more than by 1.5–2.0 times. The yearly increase in the number of failures is due to the deterioration of road conditions in the warm season. Melting p ermafrost causes an almost semiliquid mixture of water and various types of soil and sand in the work zone. The load-bearing capacity of soilwo rsens. The wheels of moving dump trucks make deeper track on th e road surface. This results in the increased loads imposed on the components and assemblies of the chassis, transmission and hydraulic system. The chassis components and parts, which have no closed (isolated) lubrication system, are subje cted to abrasive wear because of dirt getting into them. The data on the dump truck failures per the components and aggregates, as well as on the number of failures subject to the season and dump truck service life are obtained. Th e implemented studies into reliability of dump trucks in placer mining in the permafrost zone allow recommending balancing the seasonal variation in the number of failures by production scheduling with regard to the 75 % increase in the maintenance efforts in the warm season. For achieving efficiency and rhythmicity of placer mining operations in the warm season, it is necessary to take into account deterioration of road conditions, which affects the working capacity of dump trucks.