Hydrophobic　symmetric　flat-sheet　membranes　of　polyvinylidene　fluoride　(PVDF)　for　use　in　vacuum　membrane　distillation　(VMD)　were　successfully　fabricated　by　the　vapor-induced　phase　separation　(VIPS)　method　using　the　double-layer　casting　process.　To　avoid　the　delamination　that　often　occurs　in　double-layered　membranes,　the　same　PVDF　polymer　was　employed　in　both　the　upper　layer　and　support　layer　casting　solutions.　Solutions　with　low　and　high　PVDF　contents　were　co-cast　as　the　upper　layer　and　support　layer　of　the　membrane　that　was　formed.　In　the　VIPS　process,　the　low　PVDF　content　solution　favored　the　formation　of　a　layer　with　a　porous　and　hydrophobic　surface,　whereas　the　solution　with　a　high　PVDF　concentration　favored　the　formation　of　a　layer　with　high　mechanical　strength.　The　effect　of　the　vapor-induced　time　on　the　morphological　properties　of　the　membranes　was　studied.　As　the　vapor-induced　time　was　increased,　the　cross-section　of　the　membrane　changed　from　an　asymmetrical　finger-like　structure　to　a　symmetrical　sponge-like　structure,　and　the　surface　of　the　membrane　became　rough　and　porous.　The　membrane　subjected　to　the　longer　vapor-induced　time　also　exhibited　a　higher　permeating　flux　during　the　VMD　process.　The　best　PVDF　membrane　fabricated　in　this　study　had　a　mean　radial　pore　size　of　0.49　mu　m,　and　the　rough　upper　surface　produced　a　static　contact　angle　of　145　with　water.　During　the　VMD　process　with　a　3.5　wt.%　sodium　chloride　(NaCl)　aqueous　solution,　the　best　membrane　that　was　fabricated　produced　a　permeating　flux　of　22.4　kg　m(-2)　h(-1)　and　an　NaCl　rejection　rate　of　99.9%　at　a　feed　temperature　of　73　degrees　C　and　a　downstream　pressure　of　31.5　kPa.　This　performance　is　comparable　to　or　superior　to　the　performances　of　most　of　the　flat-sheet　PVDF　membranes　reported　in　the　literature　and　a　polytetrafluoroethylene　membrane　used　in　this　study.