A cell search method and apparatus for an asynchronous mobile communication system are provided. A Secondary Synchronization Code (SSC) correlator despreads a signal at every slot boundary in accordance with a z-sequence to output a SSC correlation value. The signal is received over a first symbol duration. A Primary Synchronization Code (PSC) correlator despreads the received signal in accordance with a PSC to output a PSC correlation value. A dot product calculator performs dot product calculation between the SSC correlation value and the PSC correlation value to output a correlation result of the SSC. A frame synchronization detector extracts frame synchronization information from the correlation result.