Poly(gamma-methyl L-glutamate) and a homologous series of poly(gamma-n-alkyl L-glutamates) (PnALGs) including only the even (n = 2, 4, 6, 8, 10, 12, 14, and 16) members of the series have been studied by dilatometry, differential scanning calorimetry, and dielectric measurements. The glass transition temperature has been related to the number of methylene groups in the outer part of the n-alkyl side chain (including the terminal methyl) of the repeating unit. A semiempirical equation has been used that affords estimates of T-g in good agreement with the experimental data The melting points and enthalpies of the crystalline members of the series were analyzed. For melting points a good fit of a Garner plot by a least-mean-squares procedure is obtained with T-m degrees = 407 K, a = -6.04, and b = -3.49. The contribution to the melting enthalpy per methylene unit clearly demonstrates that only part of the n-alkyl side chains form a crystal lattice. In amorphous members of the series, i.e, polymers with short side chains when n = 1, 2, 4, 6, 8, and 10, a dielectric relaxation (called beta-relaxation) has been found at temperatures near and over the glass transition temperature of the side chains (T-g). In polymers with long side chains the strength of this relaxation decreases due to side chain crystallization. In polymers with shorter side chains a relaxation appears as a shoulder of the beta-relaxation and at lower temperatures of T-g. By study of the strength, shape, and position of the 8 peak vs temperature, both relaxations were analyzed.