A combination back strap and grip extender mountable on a grip of a firearm. The grip defines a magazine well. The combination comprises a strap positionable lengthwise along and overlying an anterior portion of said grip. The strap has first and second ends oppositely disposed. The first and second ends are removably attachable to said grip. The grip extender is mounted on said second end of said strap. The grip extender comprises a collar defining a lumen aligned with said magazine well when said strap overlies said grip.