Background and Objective: Due to malnutrition and to the raise of non-communicable diseases, agrifood industry research has entered the development of functional foods; the "Yacon" is an Andean tuber with a prebiotic potential.The objective was to evaluate the effect of spray drying on the viability of Lactococcus lactis ATCC19435 in the presence of "Yacon" as prebiotic.Materials and Methods: Initially, the prebiotic effect of Yacon on L. lactis was studied by making a growth curve in Yaconʼs nectar and by modelling data through the ComBase®; then L. lactis were spray dried in Yaconʼs nectar analyzing the influence of the entrance temperature and the maltodextrin concentration.The micro-organismʼs survival, water activity and moisture content were measured.Afterwards, the spray-drying effect over the bacteria stability in in vitro simulated gastrointestinal was tested.Results: The results show that L. lactis used fructooligosaccharides present in Yacon as a carbon source for its growth and metabolism with a viable population in a 92-98%, growth curve that fit Baranyi and Roberts model.Besides, it was possible to observe that the spray-drying technique used at 120EC-20% maltodextrin had a statistically significant effect over the bacteria stability in simulated gastric juice and bile fluids.Conclusion: Consequently, it is possible to infer that "Yacon" has a great potential to become a prebiotic product since a high fructo-oligosaccharides content was found both in the fresh root and in the powder; this is why it is cataloged as a promissory prebiotic food; beside, if probiotic bacteria such as L. lactis is added, it might be considered as a functional symbiotic powder food.