The relative static permittivities of liquids belonging to the homologous series of 1,n-dicyanoalkanes N C-(CH2)(n)-C N, n = 2 to 6, were determined as a function of temperature. At the isothermal conditions, the relative static permittivity of the compounds under study shows a uniform and rather moderate decrease with an increase of the n number, with an exception of 1,2-dicyanoethane, n = 2, the high permittivity of which distinctly departs from that dependence.