SUMMARY New volunteering traditions have presently been emerging in Lithuania. Volunteer work complements the governmental network of social security as well as satisfies relevant demands of the society. Volunteers devote their own time to satisfy the needs of other people without any pay. They establish non-governmental organizations intended to render social assistance to different social groups of the population. The objective of this paper is aimed at optimizing volunteer activities in non-governmental organizations (NGO) which provide social assistance to children. The objective of the research is to theoretically and empirically develop the motivation of volunteers, to reveal the importance of their motivation and preparation to work with children optimizing the activities of NGOs. The content of the present research includes analytical survey of NGO volunteer activities: the concept of volunteer activities NGO in Lithuania; the target of volunteering if defined as children of risky group social development; motivation of volunteer activities and preparation to work with children. Motivation theories have also been reviewed as well as motivation factors inside the organization and training of volunteers. Results of research volunteer activities in NGOs have also been presented. The outcome of the research is the following: altruistic motives and the need to socialize stimulate volunteers to volunteering activities. The substance of volunteer needs is generally formed by varying conditions of work and life. Volunteer motivation is stimulated by a person’s individual necessity to self-development, new knowledge, need to socialize, need to self-expression. Referring to volunteer motivation, the training is arranged as well as practical work with children, which is directly related with the development of volunteer specific social skills and education.