Cosmetics are products of chemical or natural origin dedicated specifically for use in skin and mucosa. The constant development of the cosmetic industry has generated the necessity to carry out microbiological analysis on the raw materials used in the industrial production of cosmetics as well as the final products, with the purpose of obtaining products of good microbiological quality. Cosmetic products are recognized to be substrates for the survival and development of a large variety of microorganisms, since they possess some of the nutrients that facilitate growth such as: lipids, polysaccharides, alcohol, proteins, amino acids, glucosides, esteroids, peptides, and vitamins. Also, the conditions of readiness (oxygenation, pH, temperature, osmotic degree, superficial activity, perfume, and essential oils) present in the cosmetic products favor microbial multiplication. Routine analyses to determine the microbiological quality of a cosmetic product include the following: Count of mesophilic aerobic microorganisms. Most probable number (MPN) of total coliforms. Count of molds and yeasts. Absence/presence of Staphylococcus aureus probe. Absence/presence of Pseudomonas aeruginosa probe.