In the present review, authors take into consideration the classification and the epidemiology of the skin and soft tissue infections (SSTIs), a set of commonly observed pathologies, which can present different features, relatively to site and localization, clinical characteristics, and aetiological agent, their severity being related to the depth of the interested sites. Given the variable presentation of SSTIs, an assessment of their incidence and prevalence is difficult. In general, the incidence of SSTIs has increased due to the ageing of the general population, the increased number of critically ill patients, the increased number of immunocompromised patients (HIV, cancer and organ transplant patients) and the recent emergence of multi-drug resistant pathogens.