Voice over Internet Protocol (VoIP) is a critical innovation technology in the globally oriented business world, which emphasizes flexibility and efficiency as means to reduce operation cost and improve service quality. Yet there is little research in the organization behavior literature investigating what factors affect enterprise decision to adopt VoIP. This study investigated significant determinants of VoIP adoption in the top 500 export-import enterprises in Taiwan. Logistic regression was used to examine four variables: top management support, environment competition, cost and business size. Specifically, the characteristic comparison of VoIP adopters and non-adopters were presented. We concluded by discussing weight ratio of VoIP adoption factor, characteristics of potential adopters and its managerial implications.