The article dwells upon the study of altruism as a special type of economic behaviour of society. The lack of a well-established approach to determine the role of altruism in economic relations and understand it as a phenomenon of economic behaviour that goes beyond the traditional concept of methodological individualism led to the formation of purpose and subject area of research. The article aims to clarify the economic essence of altruism and establish its impact on the expansion of volunteering in society. The subject of the study is the general principles and forms of altruistic behaviour, their compliance with the postulates of the economic theory of exchange and the impact on the formation of a general model of economic behaviour of society. General scientific research methods – theoretical generalisation, scientific abstraction, statistical observations (processing of secondary statistics), were used to obtain data. The economic essence of the category of altruism in the system of relations of exchange is specified based on systematisation of scientific approaches to the definition of the essence of altruism in economic and social research. It was found that altruism is one of the manifestations of the social type of economic behaviour, which occurs under the influence of social processes, the formation of civil society, increasing social responsibility. The authors defined socio-economic content of the altruistic volunteering as a form of economic behaviour shows its relationship with the charity. The place of Ukraine in the world rating of charity (World Giving Index) was investigated. The World Giving Index and the Human Development Index are compared. The paper reveals the existence of an interconnection between the Index of Charity (Giving Index) and the degree of inequality in the country (income, education, life expectancy) which is considered when determining the Human Development Index. The role of volunteering in the development of Ukrainian society is determined. Paper concludes that it is necessary to improve the state’s economic policy to provide support and expansion of the volunteering positive effect.