A new integrated model is developed for information systems planning. In this model, entitled HISSPM, a combination of the strengths of Critical Success Factors (CSF) method, Analytic Hierarchy Process (AHP) technique and Genetic Algorithms (GA) is used to identify and prioritize the required information systems. This model considers both qualitative and quantitative factors, as well as the importance of the factors to decision-makers, and can solve problems with relatively wide search space. Comparing the results of the proposed model with those of the famous available models reveals that the proposed model is valid and efficient. The model tested on a real world problem, resulting in a portfolio of prioritized information systems, under certain conditions and constraints, which have alignment with organizational goals, strategies and plans. This model can help encourge managers in optimal or near-optimal decision-making boost investments on required information systems.