Behavior of Bifidobacterium lactis BB-12 and Lactobacillus acidophilus LA-5 (Chr-Hansen) was studied during manufacture and storage of whipped ice cream. The effects of adding these bacteria on the product's flavor and cost were also evaluated. From each microorganism, 2-6 x 107 CFU/g were inoculated immediately before the mixing and freezing process. Mixture was then whipped to obtain 80-90% overrun, and then hardened at -30 to -25 °C. The product was stored for 85 days. Plate count of both probiotics was evaluated during manufacture and storage of the product. A significant population decrease (p<0,05) was found for Lactobacillus acidophilus LA-5 during the mixing and freezing process, and for both microorganisms after the complete process. Functional shelf life (plate counts higher than 106 CFU/g) was found to be 90 days. The addition of probiotic microorganisms did not significantly change the flavour of the product (p>0,05), but a 28% increase in variable costs was calculated. According to these results, the addition of Bifidobacterium lactis BB-12 and Lactobacillus acidophilus LA-5 to whipped ice cream provides an efficient way for the incorporation of probiotic microorganisms in the Costa Rican diet