A modular cheek rest assembly for a gunstock. The major members of the assembly are a low level cheek rest, a high level cheek rest, a storage container, a shotgun shell holder and a magazine holder. The low level cheek rest is the principal member that has engagement structure adjacent the bottom ends of its side walls for detachably securing the low level cheek rest to the butt stock of a firearm. There are attachment structure on the outer surface of the side walls of the low level cheek rest for disengageably attaching the other members. There is the ability to attach these members on either the right or left side depending on the preference of the user. If the high level cheek rest is needed, it nests over the top of the low level cheek rest.