Reiter syndrome occurs as a reaction to various infections, either by intracellular microorganisms (Chlamydia, Mlycoplasma) or by intestinal bacteria (dysenteric bacilli, Salmonella, Campylobacter, Klebsiella, Yersinia). Four personal observations of Reiter syndrome following yersinial infections (Yersinia enterocolitis in two cases and Yersinia pseudotuberculosis in the two other cases) are reported. Data concerning the yersinial etiology of Reiter syndrome are reviewed.