This study is part of our internal R&D project aimed at better understanding neonatal diarrhea, to allow better management of this problem with serious consequences both for the health of piglets and for the technical and economic performance of farms. The objective of this case-control study was to assess whether the microbiological quality of the unfermented soup distributed to sows was associated with the presence of recurrent neonatal diarrhea in the herd. Our study suggests that the higher the counts of total coliforms, enterococci and yeasts in soup fed to sows, the greater the likelihood of observing neonatal diarrhea in the flock. In addition, if the two microbiological criteria, total coliforms and yeasts are simultaneously degraded, the probability of observing neonatal diarrhea is maximum. This study therefore obliges us to systematically integrate an analysis of the soups distributed to sows in our diagnosis of neonatal diarrhea.