Provided is an apparatus and method for searching for a WLAN in a portable terminal. The method includes, upon registering a WLAN, mapping and storing cell information on a present position and information on the registered WLAN; comparing the stored cell information with connected cell information when entering a mode concurrently supporting a cellular network and a WLAN in a state where a connection to the cellular network is made; and searching for a WLAN using the WLAN information mapped to the stored cell information, when the stored cell information is consistent with the connected cell information.