A steady state computer simulation model has been developed to predict the performance of an absorption refrigeration system using LiBr-H2O as a working pair. The model is based on detailed mass and energy balances and heat and mass transfer relationships for the cycle components. A computer program has been developed to simulate the effect of various operating conditions on the performance of the individual components of the simulated system. These include an absorber, a generator, a condenser, an evaporator and a liquid heat exchanger. A new model is introduced for representing the absorber. Simultaneous heat and mass transfer has been considered in the absorber, instead of heat transfer only as in other works. The performance of absorber, generator, condenser and evaporator were simulated independently. The whole system was then simulated as a working absorption cycle under various operating conditions. Comparison between the present model results and manufacturer's data of the simulated system showed excellent agreement. The present simulation results were compared qualitatively with other works and were in very good general agreement.