Nonprofit organizations are integral part of the society and they have many vital roles but the most important ones include promotion of human health, environmental conservation, protection of human rights, the promotion of democracy and the promotion of education and social empowerment. Despite aforementioned vital roles, nonprofit organizations worldwide face a myriad of problems and challenges in establishing and maintaining financial sustainability. Therefore, the main aim of this paper is to research the importance of donations in financing nonprofit organizations in Croatia due to the fact that donations are along with membership fees, revenues from sales, subsidies, and grants one of most important source of financing of nonprofit organizations. Through the paper authors will analyse main types of nonprofit organizations in Croatia as well as their legal characteristics, accounting treatment and sources of financing. To examine the frequency and types of donations received from young individuals up to 30 years age range, the empirical research based on the online questionnaire was conducted. The research showed that young persons are aware of the importance of donating, volunteering and helping others but there are significant differences in the amount and types of donations.