The development of managerial skills constitutes a basic requirement for the fulfillment of the specific management functions of trade union leaders. As a result of the implementation of the current economic policy, the Cuban private sector constitutes an important economic and social actor, which makes it a new space for trade union attention. Correspondingly, the development of managerial skills in the training of intermediate trade union leaders is addressed; its particularity in the Cuban private sector. On this basis, a theoretical-methodological conceptual system of managerial skills development is conceived, which is composed of basic, complementary and motor concepts, which in their interrelation lead to explain the dynamics in the referred system, for the exercise of trade union activity in the Cuban private sector, with the respective methodology for its implementation, a proposal that during its application in the educational practice, evidenced its feasibility and relevance.