Nisin, antibiotic synthesized by Lactococcus lactis, has been widely used in food conservation; however, there is no history of its use in the preservation of ice cream. This study aimed to investigate the effect of nisin in preserving Italian style ice cream. Four treatments (control without nisin, and nisin 10, 50 and 100 ppm) were designed. The presence of E. coli, Salmonella, coliforms and mesophilic aerobics was determined by microbiological techniques at 0, 30, 60 and 90 days. The following organoleptic properties were evaluated: surface appearance, hardness, presence of ice, creamy, gumminess, presence of fat, presence of foam, strage flavors and sweetness. The evaluation was carried out by a panel of 15 tasters, using hedonic scales. No Salmonella, E. coli or coliforms were detected in the samples, apparently for the cleanliness of raw materials, the process of preparation and storage at low temperatures. Nisin reduced the growth of aerobic mesophilic bacteria, particularly at 90 days. Nisin treatment did not cause significant changes in the organoleptic properties, except for sweetness after 60 days, probably due to the incorporation into the ice cream of products from microbial cell disintegration.