In　a　manufacturing/remanufacturing　leasing　system,　quality　of　collected　end-of-life　leased　products　is　uncertain　due　to　lessees-differentiated　demands.　Quality　affects　remanufacturing　cost　and　degradation　level　of　remanufacturing　equipment,　which　in　turn　affects　production　and　maintenance　decisions　of　equipment　and　carbon　emissions　during　manufacturing/remanufacturing.　A　production　and　maintenance　decision-making　model　is　proposed　to　maximise　lessor＇s　profit　by　considering　production,　maintenance,　carbon　emission　costs　of　manufacturing/remanufacturing　equipment,　inventory　and　maintenance　costs　of　leased　products.　The　optimal　production　quantity　and　preventive　maintenance　(PM)　period　for　manufacturing/remanufacturing　equipment,　and　remanufacturing　cost　threshold　of　leased　products　are　obtained　by　solving　the　model　with　particle　swarm　optimisation　algorithm.　The　impacts　of　lease　period　and　PM　period　for　leased　products　on　the　decision-makings,　lessor＇s　profit　and　carbon　emissions　are　analysed.　The　results　show:　(1)　as　remanufacturing　cost　threshold　rises,　more　remanufactured　products　shall　replace　new　products,　and　PM　period　for　remanufacturing　equipment　is　significantly　shortened;　(2)　lessor＇s　profit　increases　first　and　then　decreases　as　remanufacturing　cost　threshold　increases,　while　carbon　emissions　during　manufacturing/remanufacturing　always　decrease;　(3)　remanufacturing　cost　threshold　shall　be　set　within　a　moderate　range　to　balance　the　production　and　maintenance　costs　of　manufacturing/remanufacturing　equipment;　(4)　extending　the　lease　period　and　adopting　the　optimal　PM　period　for　the　leased　products　can　improve　lessor＇s　profit.　Strengthening　PM　for　manufacturing/remanufacturing　equipment　can　reduce　carbon　emissions.　©　2024　Elsevier　B.V.