ABSTRACT: Variant strains of Salmonella enterica serovar Typhimurium, lacking one or both flagellar phases have been widely reported. The monophasic S.1,4,[5],12:i:- variant has emerged worldwide in the past few years and has become one of the most frequently encountered in many countries. In contrast, monophasic S.1,4,[5],12:-:1,2 and nonmotile S.1,4,[5],12:-:- strains are rarely described. This study investigated seven molecular markers to identify and delineate monophasic S.1,4,[5],12:i:- (n = 90), S.1,4,[5],12:-:1,2 (n = 25), nonmotile S.1,4,[5],12:-:- (n = 17) strains, and some serovar Typhimurium strains (n = 124) collected through the French Salmonella network between 2001 and 2010. Three markers were commonly detected in serovar Typhimurium and in all variant strains: STM2757, mdh and fliA-B