Long Term Evolution (LTE) is the latest cellular system that is being standardized by the 3rd Generation Partnership Project (3GPP) and is expected to substantially improve end-user throughput and reduce user plane latency, while at the same time significantly improve user experience with full mobility. To realize these expectations, 3GPP is investigating the relay station (RS) usage in LTE networks, which is an intermediate station placed between a Mobile Station (MS) and evolved Node-Bs (eNode-Bs). The RS positioning is an important factor that severely influences the LTE uplink performance. This paper analyses the impact of RS positioning on the LTE uplink performance at flow level by using numerical and simulation experiments. © 2012 IEEE.