In this paper, we analyze the outage performance of an opportunistic decode-and-forward (DF) relaying coded cooperation network over independent, and identically distributed Nakagami-m fading channels. In this scheme, cooperative diversity gain is obtained by integrating opportunistic relaying (OR) selection with channel coding. We have derived an analytical expression for the outage probability (OP) of the considered coded cooperation networks for both error-free relays and errors at relays. Furthermore, for comparison, we derive an expression for the OP of a conventional OR cooperative network. For both systems, it has been observed that achievable diversity gain is the same. However, the coded cooperation scheme achieves higher coding gain than the conventional cooperative scheme. Finally, numerical results are provided showing a tightly match between the Monte Carlo simulations and analytical curves.