The complex interaction of technological development, globalisation and socio-demographic change has accelerated a structural change in the economy, resulting in a changing working environment and new forms of employment. In the field of self-employment, an emerging trend can be observed towards one-person enterprises, which already represent more than 50 per cent of all Austrian companies. The primary aim of this chapter is to analyse the rationalities of these microenterprises based on an empirical online survey of one-person enterprises in Carinthia. We find that one-person entrepreneurs are mainly driven by motives like self-realisation or working without hierarchies. However, there are also one-person entrepreneurs who have been crowded out from the (dependent) labour market and are therefore driven by economic reasons (e.g. self-employment as an alternative to unemployment). This economically driven group of one-person enterprises is comparatively dissatisfied with their professional situation, is less optimistic regarding their entrepreneurial future, and generates lower incomes.