Faecal sludge removal is critical for the long-term functionality of on-site sanitation facilities and sustained sanitation outcomes. Private enterprises are important players in providing sludge removal services in Indonesia and other countries where government does not do so. However, the extent to which sludge removal entrepreneurs can fulfil this role depends on the viability, or success, of their enterprises. This paper investigates factors linked to the success of sludge removal enterprises in Indonesia, including traits of the entrepreneurs, characteristics of the enterprises and contextual challenges. These factors and levels of success were examined from data collected from structured interviews with 24 sludge removal enterprises across six cities in Indonesia. This research found that higher levels of success were significantly associated with entrepreneurs that had previous work experience of any kind, made higher upfront investments and did not involve their family members in the management of the enterprise. Participants most frequently identified high costs of capital, high levels of competition and insufficient time to spend on the enterprise as challenges to success. These findings provide important evidence for how civil society organisations and governments in Indonesia and elsewhere may best provide a conducive enabling environment for enterprise roles in sludge removal.