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The objective of this paper work was to compare performance among foreign and local alfalfa ecotypes under Tunisian conditions, in view of improvement programme. For this goal, 20 alfalfa farm ecotypes were collected from Tunisian oases and 16 exotic cultivars were provided by PERMED project. The evaluation of agro-morphological traits on all the populations was performed during two years (2006-2008) in experimental field of Arid Regions Institute, Gabes (33.90 degrees N; 10.08 degrees E), of Tunisia. Except width of central leaflet, all agro-morphological traits were significantly different among populations (P<0.05). Higher dry matter percentage, stem length, inflorescences.plant(-1) and pods.plant(-1) were mainly associated with local populations. Exotic germplasm had advantage in fresh weight, stem number and weakness in reproductive traits. The two plans of the projection of the first, the second and the third components in the Principal Component Analysis showed an excellent separation between the local and foreign alfalfa cultivars. This shows that the variables analysed are able to explain the differences observed between the native and foreign alfalfa populations. The first axis showed that the exotic populations were distinguished by highest fresh weight yield and leaves number, strong length of central leaflet, than the native ones. The correlation study showed the possibility of selection of synthetic variety combining higher green matter yield and good digestibility or high dry and seed yield in one genotype.