Co-channel interference (CCI) has an inevitable effect on the performance of cooperative systems. It is a result of sharing the same time slot among several nodes. In this paper, we address the impact of CCI at the destination node on the performance of a dual-hop fixed-gain amplify-and-forward (AF) relay system. A noise-limited relay and an interference-limited destination are assumed in the analysis. Furthermore, the source-relay and the relay-destination channels of the desired user are assumed to be Rician distributed and the interferers' channels are assumed to follow the Nakagami-m distribution. We derive approximate expressions for the outage probability and the symbol error rate (SER) for both the independent non-identically distributed (i.n.d.) and independent identically distributed (i.i.d.) cases of interferers' fading channels. Furthermore, a look into the asymptotical high signal-to-noise ratio (SNR) performance has been taken and the diversity order and coding gain of the considered system are determined. Monte-Carlo simulations are provided to validate the accuracy of the analytical results. Main results show that the system is still able to achieve full diversity in the presence of finite number of interferers with finite powers.