Rural tourism is a collective name for various forms of tourism and activities that located outside cities, that is, in rural areas. It plays a key role in the development of rural areas because it offers the local population the possibility of additional income. It also has great significance for sustainable development because it cares about tradition, cultural heritage, the environment and natural and cultural resources. Rural tourism is of great importance for raising the competitiveness of the Republic of Croatia and extending the tourist season. The paper presents the basic determinants of rural tourism and aims to determine and analyze the current state of rural tourism in northwestern Croatia. Another aim was to point out the possibilities for its sustainable development. In the paper, research is carried out using the method of in-depth interviews with relevant interlocutors in the field of rural tourism. The research has showed that rural tourism in northwestern Croatia has great potential, but it has not been sufficiently utilized. It has also showed that, compared to coastal part of Croatia, rural tourism in northwestern Croatia has been neglected. The presented results of in-depth interviews represent a contribution to knowledge about the current state of rural tourism and the direction in which it should develop. Valorization of entrepreneurial projects, natural and cultural resources, maintaining high quality offer and including additional tourist attractions as well as mutual cooperation of all participants in rural tourism are important elements in achieving a higher level of significance of the rural areas, both for the local population and for the national economy of the Republic of Croatia.