PurposeTaking a co-creation perspective and integrating knowledge-based and resource-based perspectives, the authors examine the role of customer participation in organizational performance and project success. The authors also investigate the mediating role of knowledge integration and the moderating role of requirement risk for these relationships in uncertain contexts.Design/methodology/approachThe authors undertook two studies. The first study was carried out in 2018 in which the authors drew on survey data from 150 information technology (IT) sector employees and examined the mediating role of knowledge integration in the relationship of customer participation with organizational performance and project success. In the second study undertaken in 2020, the authors drew on data from 92 IT and telecom sector employees and examined the moderating role of requirement risk in the relationship between customer participation and knowledge integration. Study 2 was conducted during the COVID-19 pandemic when employees were largely working from home and were more sensitive to risks and uncertainty about the scope and system requirements. Both studies were survey-based, and analysis was carried out using structural equation modeling.FindingsThe authors’ two-study examination indicated that knowledge integration positively mediates the relationship of customer participation with organizational performance and project success during the co-creation process. Furthermore, the authors demonstrate that when requirement risks are high, customer participation relationship with knowledge integration is weaker.Originality/valueThe authors show that integrating customer knowledge is critical to project success and organizational performance. By identifying risk uncertainties and environmental contingencies, the authors highlight the constraints of customer participation for knowledge integration, organizational performance and project success. The authors provide some key study findings based on survey data obtained from project teams during two periods (normal and pandemic).