In response to the adjustment processes resulting from the crises of the 70s, the paradigm of «local development» is now fully consolidated, although with the predominance of the economic dimension. However, local development processes should be analyzed and conceptualized paying greater attention to the social dimension, and in particular to the relational component of social capital. From the classical division of social capital in bonding, bridging and linking, a series of concepts for a better conceptualise local development processes are introduced. A conceptual model is proposed to interpret the contribution of those different types of social capital both to the dynamic component of local development processes in tis different phases, and its sustainability. Finally, attention to the interaction of micro and macro scales is provided which, from the perspective of social capital, directly influences the institutional framework for local development.