© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Poly(vinyl alcohol) (PVA) gels, prepared by a cast-drying method, show excellent swelling and mechanical properties. However, the elution of polymers from such gels is one of the major hindrances for practical applications. In this study, PVA cast gels were prepared from a PVA powder, with a high degree of polymerization and hydrolysis, under different temperatures and humidities. The swelling ratio, elution ratio, crystallinity, and microcrystallite size were evaluated, and these were compared with each other. The lowest elution rate (<1%) was obtained under conditions of high drying temperature and high humidity. This indicates that polymer elution can be suppressed by controlling the size, number, and distribution of the microcrystallites.