In addition to the dire medical needs resulting from the 2010 Haiti earthquake, over 1.5 million people were left without access to sanitation facilities. In the second phase of the overall emergency response, Médecins Sans Frontières-Operational Centre Brussels attempted to address the urgent need for safe and sanitary human excreta disposal in some of the most neglected camps for displaced people in Port-au-Prince, by implementing an approach consisting of defecation in single-use, biodegradable plastic bags. Construction and maintenance of facilities for this intervention was undemanding and cost-effective, and the approach offered a suitable solution to a number of technical constraints encountered in this urban setting. However, immediate acquisition of ecologically appropriate bags proved troublesome. Furthermore, a relatively low bag usage rate of 13 per cent (8–18 per cent) was observed, differing considerably from the rates reported in more controlled evaluations of such approaches, reflecting the operational limitations to this intervention. We therefore recommend this sanitation approach in urban settings only as a stop-gap approach when other interventions are not possible.