Dynamic glass transition, related to the cooperative motions of amorphous polymeric segments, can be investigated by means of periodic techniques. Recently, temperature modulated differential scanning calorimetry (TMDSC) has offered the possibility to obtain α relaxation data at very low frequency (below 0.2 Hz). In this paper dynamic glass transition temperatures of an amorphous and two semicrystalline polymers, obtained by means of TMDSC, have been compared with dynamic mechanical (DMTA) and dielectric (DETA) results. The DMTA and DETA scans were performed at 3 Hz and in the frequency interval 102–104 Hz respectively. The frequency dependence of calorimetric, dynamic mechanical as well as dielectric data has been found successfully described by the Vogel-Fulcher-Tammann equation in the whole range of frequency investigated.