This paper presents a selected-mapping (SLM) based peak-to-average power ratio (PAPR) reduction technique for the interleaved single carrier frequency division multiple access (IFDMA) uplink system. The SLM is a distortionless technique as it selects the transmit signal with low PAPR from a set of alternative signals representing the same information. Extensive matlab simulations have been carried out to validate the proposed idea. At the clip rate of 10-3 with user's subcarriers M = 16, system's subcarriers N = 512 and dissimilar phase sequences V = 16: the PAPR gain of the proposed SLM based IFDMA system is 6.8 dB and 2.3 dB when compared with those of conventional interleaved OFDMA uplink systems and the conventional IFDMA uplink systems respectively, for the QPSK modulation. © Pakistan Academy of Sciences.