Asymptomatic carriage of Staphylococcus aureus is common, particularly in the anterior part of the nasal cavity. Apart from nasal and nasopharyngeal carriage, another frequent site for S aureus colonization is the skin, particularly the inguinal fold, rectum and axilla. The general prevalence of S aureus carriage is around 20-30% as reported by relevant studies in field literature. In children, data on nasal carriage appears to be somewhat similar to the prevalence reported in adults, ranging from 18.12 to 38.5 percent, but there are certain particularities and a wide variability between results from different countries and different studies. To determine the real prevalence of S aureus and MRSA strains, studies should adjust for confounding factors, as described in this article.