Antarctica is no longer a pristine environment due to atmospheric pollution, fuel spills, inadequate waste management and wastewater discharges from anthropogenic activities (Harris 1998, Stark et al. 2015). Approximately 37% of the permanent stations and 69% of the summer stations lack any form of sewage treatment (Gröndahl et al. 2009). The characteristics of wastewater from stations are also of concern because they are a complex mix of contaminants containing human waste, cosmetics, viruses, dyes, detergents, medications, chemicals from laboratories and even microplastics (Bhardwaj et al. 2018). In Antarctica, treatment plants discharge treated water into the sea and then sludge is packed and sealed into drums for later shipment to Chile. Nevertheless, sewage sludge (c. 59–88% organic matter) could become a biosolid instead of being a waste if correctly stabilized. The Ecuadorian Antarctic station ‘Pedro Vicente Maldonado’ produced c. 200 kg of sewage sludge during expeditions in 2017 and 2018. Thus, the aim of the present study was to biostabilize sewage sludge using two methods (one thermal and one biological) at the Ecuadorian Antarctic station. As a result, the stabilization of sewage sludge produced a biosolid that was easier and more cost effective to transport, avoiding odour problems.