Purpose: The aim of this paper is to characterize mutual mentoring as a tool of intergenerational staff management in the enterprise and to examine the effects of the mutual mentoring in Polish enterprises.Methodology: The research was conducted using a survey on a sample of 250 business representatives from all over Poland. The subjects were mainly CEOs or members of the management staff . The criteria for selection of enterprises for this study were: enterprise size (small, medium, large companies), the age structure of the staff . The aim of the study was to identify the process of mutual mentoring in enterprises – whether it is present and what results or benefits it brings to enterprises and their employees.Findings: Almost 40% of the surveyed employers confirm that in their firms knowledge is transferred between employees: this occurs through teaching junior employees by the senior and more experienced ones and there also occur inverse relations, i.e., junior employees share their knowledge with the senior ones. This leads to formation of the added value both for the employees and the whole business. Employers observe numerous benefits from the implementation of mutual mentoring in their organisations. The main ones include: the acquisition and development of competences and skills by employees, the improvement of work environment conducive to involvement of employees in work and the increase of team motivation.Implications: In the Polish literature on the subject the aspect of mutual mentoring in companies has not yet been discussed. The conclusions of the presented analysis provide a basis for larger and more detailed research and the development of practical recommendations for business managers.Originality/value: The author has presented a unique theory of mutual mentoring as a tool of intergenerational staff management in the enterprise. Mutual mentoring defined as modified version of traditional mentoring and involves the assumption that different generations of employees become each other’s mentors or teachers, thus ensuring mutual substantive and organisational support in the workplace as well as natural transfer of knowledge and experience within the organisation. Author presented original research results: effects of the mutual mentoring in Polish enterprises.