Six different variants of a new type of polyimide, poly(aryl prehnitimide)s, containing various moisture contents have been studied using dielectric relaxation spectroscopy. Dielectric loss measurements show the presence of a double peak near 200 K (depending on frequency) due to water relaxation. The two peaks have been designated gamma(1) and gamma(2). The gamma(2) peak appears as a shoulder on the gamma(1) peak at lower temperatures and is very sensitive to moisture content. The gamma(1) peak is less sensitive to moisture content and is associated with isolated water molecules coupled to the polymer chains. Both of the gamma-relaxation peaks were studied in detail to obtain the associated activation energies.