Considering that the domestic and international market of lacteal shows a marked trend to the obtaining milk and their Derivatives of high quality, this present investigation work had as aim determine the hygienic - sanitary quality, by means of the inventory of mesofilos aerobic and somatic cells, of Cow's milk produced in the stables of milkshed of Libertad. Samples were collected fortnightly milk 34 stables located in the irrigations of Trujillo, Paijan, Viru During the period January - December, 2012. The study shows the contents of mesophile presented an arithmetic mean (AM) and geometric (GM) of 279.523 UFC/ml y respectively; 142.575 UFC/ml, Which expires with the established for the NTP 202.001-2010 (máx. 1 x 106 UFC/mL). And it reaches a qualification of "good" according to the FEPALE. The lowest values are appreciated in the months of September to December Diciembre (AM= 240.63...