In this paper, we analyze outage probability of opportunistic amplify-and-forward (AF) orthogonal frequency-division multiplexing (OFDM) relaying over Nakagami-m fading channel. The closed form outage probability of the proposed system is analyzed at high SNR regime. Results show that the increment of relay nodes, number of multipath (L) and Nakagami fading parameter (m) improves the outage performance. The asymptotic outage probability is validated through the Monte-carlo simulations. The result is compared with other existing relaying schemes.