Recruitment and support processes in sustainability-profiled incubators have received little research attention. The article addresses this knowledge gap in an empirical investigation of three sustainability-oriented incubators in Sweden, Finland and Germany. The data are based on interviews with managers, stakeholders and tenants in Green Tech Park (Sweden), LADEC (Finland) and Green Garage (Germany). On average, the studied incubators had an ambition to recruit and develop sustainability-oriented start-ups, but the number of tenants must reach a critical mass if such ambitions are to become a reality. The local context influences this critical mass of start-ups and is a determining factor in generating (a) potential tenants and (b) the resources to support such firms. This suggests that incubator managers must actively seek tenants interested in sustainable entrepreneurship and that support must focus on activities in sustainability.