Memory devices and methods for controlling a row hammer are provided. The memory device includes a memory cell array including a word line and a plurality of counter memory cells storing an access count value of the word line, and a control logic circuit configured to monitor a row address accessing the word line during a row hammer monitoring time frame and to determine the row address to be a row hammer address when the number of times the word line is accessed is greater than or equal to a threshold value, wherein the row hammer address is to be stored in an address storage. The control logic circuit is further configured to hold up a determination operation for a next row hammer address, based on activation of a latch full signal indicating that there is no free space to store the row hammer address in the address storage.