This article analyzes the eurocommunist project developed by the Spanish Communist Party (PCE) during the seventies. The PCE’s leadership attempted to develop a new model of communism compatible with the values of pluralism and freedom, but it faced with many difficulties. During the decades of secrecy and exile within the PCE had taken shape heterogeneous ideological and organizational models that were based on different and antagonistic political cultures. The failure to achieve a synthesis, that was became evident after the legalization and even more after the closure of the stage of consensus, determined the decline of the spanish eurocommunism.