This paper studies a location– routing– inventoryproblem in a multi-period closed-loop supply chain withmultiple suppliers, producers, distribution centers, customers, collection centers, recovery, and recycling centers. In thissupply chain, centers are multiple levels, a price increasefactor is considered for operational costs at centers, inventoryand shortage (including lost sales and backlog) are allowed atproduction centers, arrival time of vehicles of each plant to itsdedicated distribution centers and also departure from themare considered, in such a way that the sum of system costs andthe sum of maximum time at each level should be minimized. The aforementioned problem is formulated in the form of abi-objective nonlinear integer programming model. Due tothe NP-hard nature of the problem, two meta-heuristics, namely, non-dominated sorting genetic algorithm (NSGA-II)and multi-objective particle swarm optimization (MOPSO), are used in large sizes. In addition, a Taguchi method is usedto set the parameters of these algorithms to enhance theirperformance. To evaluate the efficiency of the proposedalgorithms, the results for small-sized problems are comparedwith the results of the e-constraint method. Finally, fourmeasuring metrics, namely, the number of Pareto solutions, mean ideal distance, spacing metric, and quality metric, areused to compare NSGA-II and MOPSO.