The relative static permittivities (epsilon(r)) of six binary mixtures of four isomeric butanols are reported for various mole fractions over entire composition range at (288.15, 293.15, 298.15, 303.15, and 308.15) K. The excess values of er and the permittivity temperature coefficients (partial derivative In epsilon(r)/partial derivative T) have been calculated. The excess parameters have been fitted to the Redlich-Kister polynomial equation. The results of the measurements have been used in the analysis of hydrogen-bond interactions between unlike molecules occurring in the alcohol-alcohol mixtures.