Recurring respiratory tract infections are typical of childhood. This results from the fact that children are exposed to pathogens, usually in groups of people, and from the immaturity of the immune system. Most upper and lower respiratory tract infections are caused by viruses. Nevertheless, antibiotics, which target bacteria, are often prescribed. Antibiotic overuse leads to increased microbial resistance to these drugs, resulting in their inefficacy. Improper treatment of respiratory infections with antibiotics ultimately leads to treatment failure. An increase in antibiotic resistance of many bacterial strains is becoming a serious global problem and makes treatment much more difficult. It is a responsibility of each physician to use antibiotics properly and implement adequate prevention of recurring respiratory tract infections. For many years, it has been attempted to find effective agents that improve immunity in children. The pharmaceutical market offers various preparations advertised as immunostimulants, such as bacterial lysates, vitamins, dietary supplements, probiotics or herbal, animal and homeopathic products. The role of immunomodulatory substances is to promote the immune system to fight pathogens, reduce the frequency of infections and decrease the demand for antibiotics. Unfortunately, most immunomodulators do not have sufficiently reliable clinical trials that would confirm their efficacy.