The influence of Pycnogenol, French marine bark extract, added to yogurt preparation on the viability of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus and on pH, titratable acidity, macro-nutrients, and folate content were evaluated throughout the shelf life of products. At all concentrations studied, Pycnogenol additions neither significantly affected the growth of microorganisms nor caused any modification of nutritional parameters during storage in yogurt. To highlight any possible degradation of Pycnogenol components by yogurt flora, an estimation of total polyphenol contents and an evaluation of some phenolic compounds in yogurt at the greatest concentration of Pycnogenol were carried out at the beginning and at the end of the study. Our data indicates that neither total polyphenol content nor selected phenolic substances (cathechin, epicatechins, chlorogenic acid, and caffeic acid) was affected during the shelf life. In conclusion, these results suggest Pycnogenol as a valuable ingredient to enrich yogurt preparation.