In this paper, we present a scheme, called Zone-based Cooperative Caching (ZCC) for data caching in mobile ad hoc networks. In ZCC scheme, r-hop neighbors of a mobile clients form a cooperative cache zone. The objective is to improve data availability and access efficiency by collaborating local resources of mobile clients. ZCC addresses two basic problem of cooperative caching: cache resolution and cache management. In ZCC scheme, for a local cache miss, requested client looks for data item within its zone. If no client inside the zone has cached the requested data item, zone-based cache resolution process is invoked to find the cached client before reaching the server. In this scheme, for cache management, we proposed an optimistic placement for store the replace data item in requested zone. For optimistic placement, caching status and mobile client energy level status is exchanged and maintain periodically in a zone. Simulation with ns-2.32 software were used to study the performance of the system in terms of success ratio, miss ratio, average number of messages per request, and average travel distance in hops and to compare with the performance of No Cache, SimpleCache, Hop-by-Hop Cache resolution schemes. The results demonstrate the effectiveness of the proposed scheme in terms of achieved data availability and low delay for data retrieval.