OBJECTIVE: Social firms or enterprises aim to offer sustainable employment in supportive workplaces for people who are disadvantaged in the labour market. Therefore, this study sought to explore employees' views in one social firm about the features of their workplace that they found supportive. PARTICIPANTS: Seven employees were recruited, all of whom experienced persistent mental illness, and had worked in this social firm for between eleven months and six years. METHODS: A semi-structured interview, the Work Environment Impact Scale (version 2.0), was used to explore participants' views of their workplace and to rate how its physical and social characteristics impacted them. Participants also rated their job satisfaction with a modified Indiana Job Satisfaction Scale. RESULTS: Features of the social firm workplace identified by these employees as contributing to their sustained employment and satisfaction were the rewards, task demands, work schedule, and workplace interactions with supervisors and other co-workers. From their views, guiding principles for the development of supportive workplaces and evaluation of their capacity to afford sustainable employment were derived. CONCLUSIONS: This study adds to current knowledge about workplace supports from an employee perspective, and is of relevance for informing future social firm development, workplace design and evaluation.