In this study, 20 women with staphylococcal mastitis were randomly divided in two groups. Those in the probiotic group daily ingested 10 log10 CFU of Lactobacillus salivarius CECT5713 and the same quantity of Lactobacillus gasseri CECT5714 for 4 weeks, while those in the control one only ingested the excipient. Both lactobacillus strains were originally isolated from breast milk. On day 0, the mean staphylococcal counts in the probiotic and control groups were similar (4.74 and 4.81 log10 CFU/ml, respectively), but lactobacilli could not be detected. On day 30, the mean staphylococcal count in the probiotic group (2.96 log10 CFU/ml) was lower than that of the control group (4.79 log10 CFU/ml). L. salivarius CECT5713 and L. gasseri CECT5714 were isolated from the milk samples of 6 of the 10 women of the probiotic group. At day 14, no clinical signs of mastitis were observed in the women assigned to the probiotic group, but mastitis persisted throughout the study period in the control group women. In conclusion, L. salivarius CECT5713 and L. gasseri CECT5714 appear to be an efficient alternative for the treatment of lactational infectious mastitis during lactation.