OBJECTIVE: The aim of the present study was to obtain data on the microbiota of human colostrum, and to correlate it with a possible source of probiotics transferred from mother to infant during breastfeeding. METHODS: 70 samples of milked human colostrum were analyzed as to the presence of mesophylic, thermoduric, psychrotrophic, proteolytic, proteolytic-psychrotrophic, lipolytic microorganisms, molds and yeasts, Staphylococcus aureus, total coliforms, fecal coliforms, Group D Streptococcus species and lactic acid bacteria. RESULTS: the microbiological analyses revealed several classical groups of microorganisms: mesophylic (68.6%); thermoduric (38.6%); psychrotrophic (8.6%); proteolytic (15.7%); proteolytic-psychrotrophic (1,4%); lipolytic (4.3%); molds and yeasts (11.4%); Staphylococcus aureus (44.3%); total coliforms (7.2%); and lactic acid bacteria (37.2%), thus characterizing a diversified microbiota. Thermoduric-psychrotrophic microorganisms, fecal coliforms and Group D Streptococcus species were not identified in any of the samples. CONCLUSIONS: The results show a microbiota rich in lactic acid bacteria, which may work as probiotics if delivered to infants within the first days of life.