Pidotimod (3-L-pyroglutamyl-L-thiaziolidine-4-carboxylic acid) is a synthetic dipeptide with immunomodulatory properties that is indicated for use in adults and children over 3 years of age with documented cell-mediated immunodepression during respiratory and urinary tract infections. Infections are associated with an immune response that helps fight pathogens. In this scenario, inflammatory events occur to improve the antimicrobial reaction. However, defective immunity and/or sustained inflammation may adversely affect the course of the infection. Thus, modulating immune function could be a valuable option in managing patients with infections. The multifaceted mechanism of action of Pidotimod enables it to modulate innate and adaptive immunity. Extensive evidence about Pidotimod, accumulated over the last 30 years, has provided much data on the prevention of recurrent respiratory infections in susceptible children and respiratory exacerbations in patients with chronic bronchitis. Recent studies provide interesting information on how Pidotimod affects the metabolomic profiles of patients with bronchiectasis, clinical and immunological outcomes of elderly patients with pneumonia, clinical and cellular changes in patients with allergic rhinitis and asthma, and beneficial effects on cytokines and humoral immunity in human immunodeficiency virus (HIV) patients. Preliminary experience suggests that Pidotimod can shorten the duration of COVID-19 infection and reduce clinical severity by modulating the immune response, as well as prevent vaccination-related adverse events. In conclusion, the immunomodulatory properties of Pidotimod indicate that it may be a valuable option in managing patients with respiratory infections and other immune-mediated disorders, including allergy, chronic obstructive pulmonary disease, and asthma.