Mathematical Morphology (MM) has been introduced in geographical sciences during the years 1970-1980. However it did not find the same echo in the geographer community according the areas of research. Unlike remote sensing where MM tools have been used as early as in the eighties and are nowadays widespread, in the research works resorting to spatial analysis and modelling, MM is much rarer. And yet morphological analyses exactly match the purpose of spatial analysis. This talk aims to demonstrate the relevance of MM in geography and more precisely in spatial analysis. The three applications proposed focus on socio-economic issues: urban zones of influence detection, regional differentiations analysis and spatial modelling. Finally, are highlighted and discussed the major shortcomings which hold up the spread of MM in geography, planning and geomatics.