A semiconductor memory device includes a memory cell array and a main controller. The memory cell array includes a plurality of memory bank arrays, and each of the memory bank arrays includes a plurality of pages. The main controller counts a number of accesses to a first memory region of the memory cell array, generates at least one victim address of at least one neighbor memory region that is adjacent to the first memory region and performs a scrubbing operation sub-pages of the pages corresponding to the at least one victim address when the counted number of accesses reaches a first reference value during a reference interval.