This paper aims to determine the constraining and enhancing factors of key business enterprise in Occidental Mindoro, Philippines. The Michael Porter's Diamond Model of Competitive Advantage was used as the analytical framework. Data obtained from the survey were analysed using Descriptive Statistics. The research revealed that businesses are negatively constrained by three most critical factors such as insufficient and unreliable electric supply, unfavorable tax system and the cost of transport which is very important since Occidental Mindoro is an island province. The enhancing factors, on the other hand, are the incentives in the compensation of management, favorable market size and the nature of competitive advantage which are unique among industries. However, this study also revealed that the environment for the business enterprise is not enabling because majority of the competitive determinants showed competitive disadvantage.