The humanitarian catastrophe in the Horn of Africa early 2011 led to a high influx of Somali refugees to the Liben camps. After its involvement in the emergency response, MSF-OCA deployed huge resources in Liben to bring the devastating situation under control. This evaluation report looks at the programmatic and strategic choices of the OCA intervention. MSF managed to get the mortality situation in the respective camps under control despite remarkable human resource gaps and restrictive regulatory mechanisms limiting access to the beneficiaries. Due to the correct priority setting of programmes, MSF could achieve this success in spite of the challenging environment and the specific health-seeking behaviour of the target populations. The investment in understanding of cultural behaviour of populations and development of clear communication strategies for different stakeholders were supporting MSF’s role and its acceptance.