Employees' engagement, manifested as physical, cognitive and emotional participation, is the main driving force in an organisation's working environment. Employee's engagement has been increasingly studied in scientific and professional circles due to its importance for the success of an organisation. The impact of engagement on employees' work and their effectiveness is presented through a scientific and theoretical approach. The aim of this thesis is to analyse the methods and means which organisations should use to have engaged employees, to determine their purpose in the organisation, their basic values, and the main characteristics of the fulfilment of their tasks. The research leads to the conclusion that in order for an organisation to be successful all the employees need to be interconnected, while the management has to act by communicating, motivating, informing and getting to know employees. Engagement is important for the whole organisation because it incites cooperation and effectiveness, which attracts new customers and is desired by new employees.