This paper proposes a method for transmitting data through a best relay selection technique in a cooperative network over Nakagami-m fading channels. The selection of the best relay among multiple Decode and Forward (DF) relays is based on the minimum outage probability (Pout) criterion. Therefore, only the relay with the lowest Pout will transfer the data to the destination. A closed-form expression is derived for the Pout of the best relay selection with the DF technique. Numerical examples are presented here for demonstration.