Past two decades have seen increasing research in the broad area of beneficial non-task employee behaviors. Several concepts have been proposed to capture such behaviors, like organizational citizenship behavior (OCB), prosocial behavior, organizational spontaneity, extra-role behavior, contextual performance, etc. But "contextual performance" (labeled here as organizational citizenship performance, meaning behaviors that support the organizational, social and psychological environment in which the technical core, i.e., task performance, must function) has emerged as the best specified concept (Organ, 1997). Despite the emphasis by scholars on the twin needs of construct validity and developing culture-specific measures for concepts like OCB, progress is lacking in this direction. This study aims to fill this gap. The research design involved three broad stages: item generation, scale development and assessment of scale's psychometric properties (reliability and validity). Fulltime and paid employees of several NGOs participated in data collection. The emerging scale shows satisfactory psychometric properties. It is expected that this scale would be useful for research as well as practice. Besides bridging the research gaps mentioned above, NGOs can use it to measure organizational citizenship performance. With some modifications, this scale is expected to be useful for other Indian organizations as well.