MANET is considered as an infrastructure less data network where the nodes can behave as source or router (packet forwarder) which helps the network to cover the longer distances with low power transmission. Since it does not require any centralized controlling system and can organize itself without external interfere it's a preferable choice for the small battery operated clustered system such mobile and PDA. The self-organizing nature of MANET makes it very flexible and dynamic which can adopt variety of system configuration. Although to provide such services the protocols designed for MANET contains many security loop holes which makes it prone to network attacks and easy target for attackers. Although many types of active and passive attacks currently known, this paper focuses on Sink-hole attack which is a sub-category of Black-hole attack. The sink-hole is considered as one of the most serious attacks in MANET because it force the traffic to pass through attackers node by manipulating the routing protocol and then node drops all the traffic, which causes degradation of networks performance. This paper present an individual trust managing technique to prevent against sink-hole attack. The proposed algorithm is simulated using network simulator NS2 and the results shows that the proposed algorithm greatly reduces the sink-hole impact and performs much better than previous algorithm. General TermsSinkhole attack, trust management technique.