As humanitarian disasters increase as a result of extreme natural disasters, civil participation and self-help in disaster relief is becoming increasingly important. However, research on disaster volunteering is currently limited. This thesis contributes to the literature by examining personal and situational influencing factors of helping behaviour in disasters. In particular, this research addresses two main questions: What motivates people to help in exceptional social situations? And what social characteristics influence the access to disaster relief? The theoretical foundation of the investigation is based on a social psychological concept of motives complemented with a resource-orientated approach. The empirical analysis draws upon primary survey data from a sample of a of 1253 Austrian disaster volunteers. A majority of the respondents perceives value based motives, such as reciprocity, compassionate helping or social responsibility, as main drivers to engage in disaster relief. Besides expectations of learning effects and increased self-esteem, prior experiences with disasters are also found to play an important role in the individuals? motivations to help in disaster relief. The most important factors that influence disaster volunteering are volunteer work experience, resource endowment (education, job, income and social capital) and pro-social values. The educational level, and the labour-force participation and volunteer rate of the study?s sample were considerably higher than in the general Austrian population. A majority also rates altruistic values, social responsability and generalized trust as very important. To sum up five relevant dimensions of helping behaviour are identified: (1) socio-economic ressources, (2) pro-social attitudes (3) value based and learning motives, (4) volunteer work experiences and (5) prior experiences with disasters.