This cross-sectional study investigated the interactive effect of uncertainty avoidance cultural values and leadership styles (paternalistic, authentic and democratic) on open service innovation. Validation of open service innovation scale in Eastern context was another major objective of this research. Confirmatory Factor Analysis and cross-validation techniques revealed that Malaysian culture considers open service innovation on four dimensions instead of six dimensions proposed by Rangus, Drnovsek, and Di Minin (2013). Moreover, linear and multiple moderated regression analysis performed on a random sample of 422 medical professionals working in hospitals revealed that paternalistic, authentic and democratic leadership styles positively stimulate the open service innovation. Malaysia is low uncertainty avoidance collectivist culture, so the results of this study empirically proved that lower level of uncertainty avoidance will play its positive role to adopt open service innovation in the organization. Practical implications and future directions are provided.