In order to optimize the properties of PVDF/nanoclay nanocomposite membrane, the impact of casting conditions on membrane properties including PVDF crystalline phase, membrane morphology, mechanical strength and nanoclay retention were investigated. Nanoclays with hydrophilic modifiers tended to form membranes with larger macrovoids and higher beta-phase, and nanocomposite membranes with Nanomer (R) 1.30E, which has a simple single alkyl group on the ammonium ion as organic modifier, had the highest nanoclay retention. Long air exposure time prior to immersion had a negative impact on nanoclay retention while adding sodium chloride to the quench bath helped retain nanoclay. Despite the slight changes, nanoparticle retentions varied from 32% to 48% for all membranes tested relative to the respective original concentration in the dope. Mechanical strength of the membranes was associated with membrane morphology, which was controlled by various casting conditions. Increases in air retention time, decreases in quench bath temperature and casting at high humidity increased the demixing rate which resulted in membranes with large macrovoids and poor mechanical properties including low tensile strength, ductility and stiffness. To form good membrane structure, polymer concentration and molecular weight of PVDF has to be high enough to provide the necessary viscosity in the dope. Casting conditions should be chosen carefully not only to retain more nanoclay for economic reasons but also for the morphology and mechanical strength needed for the required applications. (C) 2014 Elsevier B.V. All rights reserved.