The viscoelastic behavior of poly(cyanate epoxy) has been investigated by dynamic mechanical analysis and thermostimulated creep. First, the coherence of both sets of data has been shown. The analysis of the fine structure of the low temperature retardation mode has revealed the existence of four cooperative sub modes. The high temperature retardation mode corresponds to the anelastic manifestation of the glass transition. The elementary processes constituting this mode are characterized by retardation times following a compensation law with a compensation temperature T-c similar to T-g + 60 degrees. The broad range of activation enthalpies reveals that cooperative movements are highly delocalized. The compensation parameters together with the range of activation enthalpy define the microstructure of poly(cyanate epoxy) and allow us to follow its relationship with the viscoelastic behavior.