Strict sanctions on the part of a number of Western countries, increased tension in the international situation and the obvious need for an innovative type of economy in our country make the problem of assessing the degree of sustainability of innovative development of industrial enterprises of the subjects of the Russian Federation especially urgent. In this article, as a way of solving the indicated problem, we propose a methodology we have developed for calculating the index of sustainability of innovative development. The purpose of the study is to assess the degree of sustainability of innovative development of industrial enterprises using the example of the Nizhny Novgorod region. The study is based on methods of statistical analysis, as well as methodological principles of the system approach, which assumes a holistic view of the problem under study. In the course of the research, the analysis of the existing approaches to the assessment of the sustainability of innovative development of industrial enterprises in the region was conducted, as a result of which the required aspects were identified, taking into account the methodology we have developed for calculating an integrated system-built innovation index of industrial enterprises in the region, including an assessment of the investment attractiveness of the regional industrial sector, evaluation of the innovative-oriented financial component, the innovative results and the innovative activity of industrial enterprises. The developed technique was tested and verified on the example of the Nizhniy Novgorod area. Conclusions are drawn on the need to raise the level of innovative development of the industry at the level of the constituent entities of the Russian Federation, and a list of measures aimed at increasing the effectiveness of innovative activities of industrial enterprises in the Nizhny Novgorod region is formulated. Practical application of the developed methodology will allow to identify the "problem areas" that impede the transition of our country's regional economy to a new innovative model of development based on the generation and dissemination of knowledge.