Corporate environmental management attention is shifting from clean technologies and pollution prevention to green product development (GPD). As a result, firms consider GPD critical for their increased productivity, cost reduction, better use of input resources, mitigation of waste disposal and become environmentally friendly. This research measures the effects of the best practices of environmental management - pollution prevention technologies, innovation and early timing - on GPD; and to analyze whether the moderating role of organizational capital strengthens/weakens that relationship. Data was collected systematically from companies involved in GPD in Thailand. Hierarchical regression techniques were used for data analysis. Findings revealed the influence of innovation in pollution prevention technologies and early timing on GPD. Interaction of organizational capital further strengthened the effects early timing had on GPD. Contrary to research hypothesis, pollution prevention technologies did not facilitate GPD. Data didn't reveal the moderating effects of organizational capital on the relationship between pollution prevention technologies, innovation in pollution prevention technologies and GPD. Although, we did not hypothesize for the organizational capital, yet data revealed its direct impact on GPD. The findings also discuss the theoretical and managerial implications for modern managers.