In today’s world mobile agents and mobile ad-hoc networks are the two technologies that are contributing towards better connectivity and communicability. When the two technologies used jointly, the interest is increased. Due to the properties like self-configuration and infrastructure-less, the mobile ad-hoc networks provide various remarkable features. But the various challenges are also associated with mobile ad-hoc networks like dynamic topology, mobility, energy constraint etc. Mobile agent provides solution to these challenges. A mobile agent is a new way of computer interactions and provides better options for the developers to create applications based on connectivity. Mobile agents move around the ad-hoc networks in a different and better way than the other widespread client server architecture based applications. Due to their mobility and autonomy these agents can perform various functions in mobile ad-hoc networks like topology discovery, routing, key management, congestion control etc. The paper reviews the role of the mobile agents in the mobile ad-hoc networks, and emphasizes its application on the various layers of a layered architecture of mobile ad-hoc networks and concludes its merits as compared to other conventional approaches.