Differential scanning calorimetry has been used to study the room-temperature transitions and melting of native and melt-crystallized tetrafluoroethylene-hexafluoropropylene (TFE-HFP) copolymers from aqueous dispersion polymerization, with low comonomer contents (between 0.15 and 0.8 mol% of HFP). At least three clear room-temperature transitions are observed for the native polymers suggesting, according to previous evidence, the coexistence of two crystalline components. Also the behaviour after annealing at the melting temperature of the melt-crystallized samples has been investigated. Conclusions are drawn concerning the morphology of the native and melt-crystallized polymers. An interpretation of the melting peaks in the light of the suggestions given by the room-temperature transitions is suggested.