Mauritania is vulnerable to climate change due to its location along the Sahel, the desert climate of the Sahara, and its socio-economic characteristics. To support the identification of climate change adaptation measures in Brakna and Assaba in Mauritania, a spatial assessment of vulnerability to climate change targeting the livelihood sectors of agriculture and pastoralism was carried out. Based on the identification of relevant drivers of climate change vulnerability in a broad consultation process among national and local stakeholders, a variety of geospatial indicators were identified and integrated in the assessments based on a standardized vulnerability assessment approach. In this paper, we provide a reflection on the methodology applied and identify lessons to be learnt on data quality, spatial scales, aggregation and visualizations. The primary conclusion is that users of the assessment results and stakeholders need to be engaged in the entire assessment process in order to reflect local characteristics more fully, and to ensure that the results are reflected in informed decision-making.