Based on interviews with a national sample of Cuban workers, hypotheses on the relationship between work discontent, “estrangement” in the specifically Marxian sense, and revolutionary political attitudes are tested.We find that attitudes toward plant administration, and perception of opportunity for promotion or higher wages in the plant are directly related to support for the revolution.The change the workers reported in their attitudes toward work since the nationalization of industry directly relates to their attitudes toward the revolution: Those whose work attitudes became positive after nationalization are most likely to support the revolution. Viewed differently, the relationship is also direct: Revolutionary workers are most likely to have changed their attitudes toward work from negative to positive. Empirical evidence and theory suggest that changes in work and work attitudes led to support of the revolution, rather than the reverse. Even with prerevolutionary employment status controlled, those whose work attitudes became positive after nationalization are most likely to be revolutionary workers.Types of work discontent are specified, and we find that prerevolutionary “estrangement” from work is even more strongly predictive of revolutionary political attitudes than other types of work discontent.