A hydrogen intake assembly for a hydrogen internal combustion engine characterized in that the hydrogen intake assembly includes at least one air intake manifold comprising an air intake pipe comprising at least one air inlet and air outlets, air intake runners comprising air inlets and air outlets, a spacer having a wall defining an inner chamber receiving a mixture of air, water and hydrogen and comprising air inlets and mixture outlets delivering said mixture, a water rail comprising at least one water inlet and water outlets, said water outlets being embedded in the wall of the spacer and a hydrogen rail comprising at least a hydrogen inlet and hydrogen outlets.