In a battery pack structure for electric vehicles that battery modules and a controller for battery management are mounted in a battery-pack-case internal space, a first one of clearances, ensured when the battery modules are mounted in the case internal space, which first clearance extends in a first direction, is configured as a first temperature-adjustment air passage, and the second clearance, located downstream of the first temperature-adjustment air passage and extending in a second direction different from the first direction, is configured as a second temperature-adjustment air passage. The controller is arranged at a position facing the second temperature-adjustment air passage. A harness for connecting between each detection line terminal from the battery modules and the controller, and one end of the harness, which harness end is configured as harness terminals connected to the respective detection line terminals, are wired along and arranged in the second temperature-adjustment air passage.