In the present paper we focus on the miscibility and crystallization behavior of mixtures of poly(tetrafluoroethylene) (PTFE) and poly(tetrafluoroethylene-co-perfluoroalkylvinyl ether)(PFA). PFA is a random copolymer of tetrafluoroethylene and a small amount of perfluoropropylvinyl ether. Although miscibility is difficult to assess directly due to the uncertain origin of the mechanical alpha-transition, the crystallization and melting behavior of the blends points to significant mixing. Under most crystallization conditions investigated, PTFE and PFA were found to crystallize in distinguishable crystalline regions, with PTFE acting as an effective nucleant for at least a portion of the PFA. Under very rapid crystallization conditions, DSC data indicate that PTFE and PFA cocrystallize, lending further support to the idea that the polymers are well mixed in the melt.