Mobile ad-hoc networks are self-configuring wireless networks without any specific infrastructure. MANETs are highly subjected to several attacks due to continuously changing network topology, lack of central monitoring and lack of efficient defense mechanism. Selfish nodes in MANETs are the defective nodes which drop the packets that are not intended to them. A malicious selfish node is introduced in the network to analyze the selfish node attack and a prevention algorithm for selfish node attack is also suggested. For the analysis, the routing protocol used in this paper is AODV. Network parameters meters like throughput, end to end delay and load are evaluated and compared. Simulation tool used in this paper is Riverbed Modeler. © 2006-2015 Asian Research Publishing Network (ARPN).