Experimental densities, rho, viscosities, eta, speeds of sound, nu, and relative permittivities, epsilon(r), for three binary mixtures of water + 2-pyrrolidinone, + 1-methyl-2-pyrrolidinone, and + 1-vinyl-2-pyrrolidinone were measured over the entire composition range and at different temperatures. The variations of rho, gamma, and nu with water mole fractions were typical of systems which show large nonidealities. The excess molar volumes, V-m(E) excess isentropic compressibilities, kappa(s)(E), and deviations in dynamic viscosities, deltaeta, and relative permittivities, deltaepsilon(r), were calculated, and their compositional variation was mathematically represented by a Redlich-Kister type equation. The partial molar volumes of water at infinite dilution, (V) over bar (infinity)(1), were calculated from the smoothed V-m(E) values of three binary mixtures at different temperatures. The variation of the Kirkwood correlation factor, g(K), was examined across the entire composition range. The analysis of these functions revealed that both hydrophobic and hydrophilic hydrations are responsible for the complex nature of the thermophysical behavior in these mixtures.