Abstract The dielectric constants and losses of 2-alkanol (n=4–8), 2-methyl-2-alkanol (n=3–7), six isomeric methylheptanols, and five isomeric nonanols have been measured at the frequencies from 1.35 to 4500 MHz at 15, 25, and 35 °C. The absorption has been resolved into two or three different Debye-like dispersion regions. The first, low-frequency, dispersion region could not be observed for more sterically hindered alcohols, such as several tertiary alcohols. For each alcohol, four concentrations of a linear hydrogen-bonded chain polymer (C1), a chain dimer and trimer (C2), a free monomer (C3), and a nonpolar cyclic polymer (CR) were evaluated by applying a modified Kirkwood–Fröhlich equation to each dispersion region. The equilibrium between C1 and C3 can be considered for more polar alcohols and that between CR and C3 for more sterically hindered alcohols. The mechanism of the relaxation process is discussed in terms of observations of the magnitude and relaxation time for the first region. The free energy of activation increases with increasing alkyl chain length, being about 20–23 for the first region, 16–18 for the second region, and 9–12 kJ mol−1 for the third region.