Computer-based analysis tools for forensic assessment of reinforced concrete structures are presented. The analysis tools, mostly in the form of nonlinear finite element procedures, are based on the concepts and formulations of the Modified Compression Field Theory. Relevant details regarding their formulation are provided. Development of realistic constitutive models and corroboration of the analysis procedures, through comprehensive experimental programs, are discussed. Also presented are graphics- based pre- and post-processors, which are of significant aid in structural modeling, input of data, and interpretation of analysis results. The details and results of a case study, illustrating the application and value of such analytical tools, are also discussed. Computer-aided nonlinear analysis of reinforced concrete structures has undergone tremendous advancement since initial applications about four decades ago. Much research activity has occurred in the realm of constitutive modeling of reinforced con crete and in the development of sophisticated analysis algorithms. These advancements are well documented in various state-of-the-art reports (for example, ASCE (1982)), and are still the subject of many specialty symposia and workshops. One particularly powerful and popular approach to advanced modeling involves the use of nonlinear finite element analysis (NLFEA) techniques. The development of such procedures has progressed to the point where they are becoming practical tools for design office engineers. Advanced analytical procedures are finding application as useful forensic analysis tools in relation to damaged or ageing structures. NLFEA procedures can be used to obtain an assessment of the safety and integrity of damaged or deteriorated structures, or structures built to superceded codes, standards, or practices deemed to be deficient today. They can be of value in assessing the behavior expected from retrofitted structures or in investigating and rationally selecting among various repair alternatives. In cases of structural failure or collapse, NLFEA procedures can be invaluable in determining the contributing factors and in suggesting remedial measures for future designs. There remain some concerns with the use of these advanced methods, however. Accurate modeling of the complex behavior of reinforced concrete remains elusive, with many conflicting