In this paper, the performances of the organic Rankine cycle system using zeotropic mixtures as working fluids for waste heat recovery in the cement plant are evaluated based on the exergy analysis. First, a mathematical model based on energy, exergy, exergoeconomic and exergoenvironmental approaches is developed in Matlab software; the model includes mass, energy and exergy as well as cost and environmental balances for each system component. The effect of significant system parameters on the organic Rankine cycle performances is evaluated as well. The performances considered are exergy efficiency, cost per exergy unit and environmental impact of the net produced power. A multi-objective optimization approach is applied to achieve the system optimal operating conditions. This approach which is based on the particle swarm algorithm is applied to find a set of Pareto optimal solutions. A final optimal solution is selected in a decision-making process. Finally, a performance comparison between zeotropic mixtures and pure fluids is conducted. The results show that the turbine inlet pressure and the mixtures concentration have significant effects on the ORC system performances. In addition, the optimization results indicate that the zeotropic mixture of cyclohexane/ toluene has the best thermodynamic and economic performances, while the best environmental performance is achieved with benzene/toluene zeotropic mixture. Compared to pure working fluids, the ORC with the mixtures as working fluids shows significant improvement in economic and environmental performances but worse thermodynamic performance.