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Extinction versus backscatter relationships have been derived at 351 nm for spherical and non-spherical desert aerosols, to investigate the role of the mineral aerosols non-sphericity on the derived relationships, lidar ratios, and aerosol optical depths. The comparison of numerical results and experimental Raman-lidar data retrieved from 38 dust outbreaks monitored over southeast Italy along the EARLINET Project, has revealed that the particle non-sphericity plays an important role when desert aerosols are directly advected to the sampling site with little contamination by anthropogenic and/or maritime aerosols. 60% of the observed dust events were in this category. On the other hand, when North African air masses exhibit a long residence times over the Mediterranean Sea and/or overpass the European continent before getting to the lidar site, the best accordance between experimental and numerical data was reached adopting the dust spherical extinction versus backscatter relationship.