Information systems outsourcing (ISO) is the contracting of technology related resources delivered over the Internet. It has an enormous potential and capability to improve business processes and technological innovations for companies. This paper seeks to investigate the factors that affect the adoption of ISO by comparing the effect across two business areas: human resources and finance. Based on the combination of a technology-organization-environment (TOE) framework and the diffusion of innovation (DOI) theory, we develop a conceptual model to study the determinants of ISO by both business areas. Data collected from 261 firms were used to test the proposed model. The study found top management support, perceived benefits, complexity, and competitive pressure to be determinants of ISO adoption in both business areas. Relative advantage was also found influential for finance. Furthermore, attitude toward change was found to have negative effects for both business areas.