The epidemiology of Salmonella infections in Sassari in the last four years was reported. The remarkable increase of gastroenteritis caused by uncommon Salmonella and by S. wien in 1975 and 1976 was point out: about all cases were related with 3 epidemic episodes in hospitalized patients that were notified as paratyphoid cases in 91% and as infancy's gastroenteritis in 9%. The 201 strains of Salmonella isolated from June 1975 to May 1976 belong for 91% to group B (for 80,5% to S. wien), for 2% to group C1, for 1,5% to group C2, for 5% to group D1 and for 0,5% to group E4. The hypothesis on introduction of S. wien in Sardinia were examined; the rules for limitation of Salmonella diffusion and for prevention of the endemicity of new imported strains, were examined.