In international practice, there are several project management framework methodologies, within which, as a rule, one or another model for assessing the maturity of project management is proposed. By comparing the results of the organization’s assessment with the description in the maturity model, the company gets an idea of its strengths and weaknesses and can determine priorities for its actions. At the moment, the development of project management in Russia allows us to rely only on the developments of foreign scientists, in addition, no empirical studies on this topic have been conducted in our country at present. The article presents the results of a study on the development of methodological approaches and recommendations to increase the level of maturity of companies in the field of project management. A model for assessing the maturity of a company in the field of project management has been developed, the distinctive feature of which is the availability of qualitative and quantitative assessments of each level, the relationship between the maturity levels of a company in the field of project management and the maturity levels of the project office of this company has been determined. Based on the proposed methodological approach (maturity assessment model), a project has been developed to increase maturity in the field of project management of a real company.