The paper reveals interrelations between the concepts “economic security”, “economic sustainability”, “development” and “competitiveness” of an enterprise. Based on their consideration, the paper enhances theoretical and methodological principles of establishing competitive innovation development and economic security of an enterprise. Unlike the existing ones, these principles provide for not only alternativeness but also equal significance when choosing between achievement of high levels of competitiveness, development and economic security. Application of the elaborated suggestions enables more objective formation of the policy of management of an enterprise’s innovation development under unstable conditions considering the industrial field and the market position of the enterprise. It is proven that essential elements of enterprises’ sustainable development include innovative activity, production provision, export of science-intensive products and development of high technology services, this providing for efficient levels of enterprises’ economic security and competitiveness. Under conditions of uncertainty, there are some basic functions of an enterprise aimed at enhancing its competitiveness and economic security including the following: achieving the optimal level of an enterprise’s resulting indicators and efficient “income-risk” ratio, innovative activity, ensuring the quality of an enterprise’s intellectual capital, environmental safety and meeting required social standards.