This article presents a proposal of a multithreaded core for an OSI/ISO management agents including its modeling,
simulation and performance evaluation. The proposed model i s compared against another one (unthreaded core) which is the c ommonly adopted model by the most of the network management systems. All t he modeling and simulation process were done at t he a gent core level. Therefore the performance evaluation do no t consider any effect of the communication layers, dealing with the performance of the activities related to the core of the agents applications.