Information technology has become an indispensable tool in today’s business world such that no business organization can risk ignoring its impact. Since organizations rely on IT business activities for their achievements, it is important for them to assess the maturity of these IT business activities. To assess IT business maturity, several models, frameworks and approaches have been proposed by researchers to assist in their assessments. However, all these models and framework have not been completely suitable for assessing IT business maturity since current business environment keeps changing. Therefore, this study integrates the Business-IT Maturity Model and the Four Asset Classes of IT Investments Framework to propose a new framework for assessing IT business maturity in organizations. In terms of methodology, the study elaborated the working principles and structure of the two models, followed by the construction of the new proposed framework. The study findings indicate that the proposed framework based on Business-IT Maturity Model and the Four Asset Classes of IT Investments Framework demonstrates four (4) important components: (a) the maturity levels of IT systems and activities in organizations, (b) the nature and characteristics engagement of these systems, (c) IT investment systems and (d) the business value. The research contributes very significantly to theory formulation and development in the field of information technology. In terms of practical implications, the study contributes by assisting organizational managements and stakeholders in identifying and recognizing the maturity of their IT investment systems and activities so as to plan towards goals and objectives attainments.