Recycled　aggregate　(RA)　presents　times　higher　water　absorption　compared　to　the　natural　aggregate　(NA).　The　moisture　states　of　the　RA　can　be　quite　variable　when　exposed　to　certain　environments,　which　can　largely　influence　the　performance　of　the　prepared　recycled　aggregate　concrete　(RAC).　This　paper　reviews　the　published　papers　dealing　with　the　effects　of　the　RA　moisture　states　on　the　workability,　the　mechanical　performance,　the　long-term　properties　and　durability　of　RAC,　and　discusses　the　controversy　between　different　studies.　This　paper　suggests　that　the　effects　of　the　RA　moisture　states　on　the　RAC　performance　at　the　fresh　state　or　after　hardening　should　be　considered　in　combination　with　the　water　supply　scheme　or　the　water-to-cement　ratio　as　taken　in　certain　scenarios.　Basically,　pre-wetting　RA　is　reported　to　be　beneficial　for　the　performance　of　RAC　at　the　hardened　state　in　most　cases:　higher　compressive/tensile/flexural　strength　and　lower　drying　shrinkage/autogenous　shrinkage　could　be　achieved　by　using　the　partially　saturated　RA　as　reported　in　many　references.　However,　the　use　of　the　surface-saturated　dry　(SSD)　RA　should　be　avoided　as　it　can　lead　to　great　loss　in　the　compressive/　tensile　strength　as　well　as　the　resistance　of　RAC　to　carbonation　and　chloride　ingress.　As　for　the　workability,　the　pre-saturated　RA　is　regarded　to　be　favorable　for　the　RAC　slump　when　the　mixing　water　supply　is　fixed,　while　in　the　case　with　a　consistent　total　water　supply,　using　the　dry　RA　can　lead　to　a　larger　slump.　This　paper　proposes　a　model　describing　the　water　absorption/desorption　behavior　of　RA　at　varying　moisture　states,　and　relates　it　to　the　microstructural　changes　in　the　ITZ　and　mortar　phases　so　as　to　provide　possible　explanations　for　the　RAC　performance　influenced　by　the　RA　moisture　states.　Recommendation　is　also　given　in　terms　of　the　shortcoming　and　challenges　on　this　research　topic　encountered　thus　far.