The primary aims of this paper are to review the concept of social capital and related constructs and to provide a brief guide to their operationalization and measurement. We focus on four existing constructs: collective efficacy, psychological sense of community, neighborhood cohesion and community competence. Each of these constructs taps into slightly different, yet overlapping, aspects of social capital. The existence of several instruments to measure each of these constructs calls for further study into their use as measures of social capital. Despite differences in the approach to measurement, there is general agreement that community characteristics, such as social capital, should be distinguished from individual characteristics and measured at the community level.