A method and apparatus for performing cell reselection in a wireless communication system is provided. A user equipment (UE) in an idle mode camps on a second cell, and receives reselection information for dual connectivity, which indicates cell reselection to a first cell or cell reselection to a frequency of the first cell, from the second cell. If the UE supports dual connectivity, the UE performs cell reselection based on the received reselection information for dual connectivity.