A washing machine with a balancer that may be commonly used irrespective of the size of a drum. The washing machine includes a cabinet, a drum rotatably disposed in the cabinet, an annular recess provided at the drum, and a balancer assembly mounted to the recess. The balancer assembly includes a balancer to offset unbalanced load generated in the drum during rotation of the drum and at least one balancer guide coupled to an outer circumference of the balancer to constitute the balancer assembly, the balancer guide being mounted to the recess along with the balancer so that an outer diameter of the balancer assembly corresponds to the recess.