In this paper, an Expectation-Maximization(EM) based iterative data detection method for downlink of a multicarriersystem is proposed. The proposed method has low computational cost whencompared with the other iterative ones since it does not require any matrixinversion if the requirements on users’ data are met. The performance of the resulting algorithm is compared withMinimum Mean Squared Error (MMSE) estimator in terms of Symbol Error Rate (SER)for downlink of a Multi Carrier-Code Division Multiple Access (MC-CDMA) system inthe presence of frequency selective channels using computer simulations. It isillustrated that the proposed algorithm outperforms the MMSE.