Abstract: An automatic wheelchair brake is provided which automatically locks both wheels when a patient attempts to rise from the wheelchair. While seated the patient manually operates a three-way lever brake with manually locked, manually unlocked and automatic positions. If the patient attempts to rise while the brake lever is in the manually unlocked position, the lever automatically returns to the automatic position and both wheels still lock automatically. After the patient has exited, the wheelchair may easily be moved by shifting the operating lever to the manual unlock position.