An engine device for an oxyhydrogen vehicle includes an oxyhydrogen generator for electrolytically converting an electrolyte into oxyhydrogen gas, a fuel tank for storing combustible fuel, a first pipe unit connected to the oxyhydrogen generator, a second pipe unit connected to the fuel tank, and an engine unit. The engine unit includes a cylinder block, an intake manifold, and fuel injectors. The intake manifold is connected to the cylinder block, is provided with passages, and is further connected to the first pipe unit such that the oxyhydrogen gas generated by the oxyhydrogen generator is fed into the passages. The fuel injectors are connected to the intake manifold, are further connected to the second pipe unit, and serve to inject the combustible fuel in the fuel tank into the passages.