Twenty-four dairy Leuconostoc strains isolated from French commercial starters and four reference strains were screened for 58 morphological and biochemical characters. Hierarchical clustering analysis was performed on the results of dextran production and carbohydrate fermentation tests. Most strains fitted into three clusters at a similarity level of 65% and were identified as belonging to the species lactis or mesenteroides. Fourteen strains were then selected and further characterized for their technological properties. They were examined for growth, acidification kinetics and proteolytic capacity when growing in milk, and peptidase activities and diacetyl production after growth in MRS broth. Principal component analysis was carried out to group strains and compare their technological properties. This allowed selection of strains of dairy interest. Special attention was given to the flavouring capacity of Leuconostoc lactis isolates that could be useful in designing commercial starters.