A brake pedal apparatus for a vehicle includes a pedal bracket provided on a dash panel, a pedal shaft provided on the pedal bracket, a pedal arm supported by the pedal shaft in a rotatable manner around the pedal shaft, a first engaging portion provided on the pedal arm, a push rod lever supported by the pedal shaft in a rotatable manner around the pedal shaft and connected to a push rod, and a second engaging portion provided on the push rod lever. The push rod lever or the pedal arm is movable along the axial direction of the pedal shaft, and the first and second engaging portions are capable of engaging with each other. The apparatus further includes a biasing member for biasing the push rod lever or the pedal arm in a direction for releasing the engagement between the first and second engaging portions, and a spacer member which, in a normal state, positions the push rod lever and the pedal arm, and which, at the time of collision, detects the collision for allowing movable one of the push rod lever and the pedal arm along the axial direction of the pedal shaft to release the engagement between the first and second engaging portions.