Skin and soft tissue infections (SSTIs) involve a heterogeneous group of entities with different clinical presentations classified according to several specific criteria. Because of their great variability, their incidence and prevalence is difficult to accurately determine. Yet it is generally thought that the rate of SSTIs is globally increasing due to an aging population, strictly associated with the increase in the number of critical and immunocompromised patients. The aetiology of SSTIs is also extremely variable, reflecting the noteworthy heterogeneity of their clinical presentations and their epidemiology. Gram-positive are far more prevalently than Gram-negative cocci responsible for STTIs globally considered including both aerobe and anaerobe microorganisms. The emergence of multidrug-resistance bacteria represents a serious public health threat which is making antimicrobial therapy less efficacious and more challenging by the day.