Zinc is a trace element necessary in many processes of cell metabolism and the catalytic activity of over 100 enzymes in humans. It plays a role in the immune system, protein synthesis, wound healing, DNA synthesis and cell division. Its immunomodulatory and anti-inflammatory effects have been evaluated in many studies. Zinc deficiency inhibits both innate and specific immunity, interferes with phagocytosis, intracellular killing and cytokine production by macrophages. Even minor zinc deficiencies can impair macrophage and neutrophil function. As one of the most important micronutrients included in many enzymes, zinc has an impact on the synthesis of proteins, hormones and red blood cells as well as proper functioning of the skin and mucous membranes. Zinc deficiency is a risk factor for developing asthma. Recent studies have shown that zinc supplementation can effectively suppress chronic inflammation and that zinc therapy effectively inhibits anaphylaxis. The aim of the study was to assess serum zinc levels in children hospitalised due to recurrent upper and lower respiratory tract infections and atopic diseases. The study showed lower zinc levels in 30% of children. This deficiency was greater in children with recurrent infections compared to children with atopic diseases. It was observed that the higher the specific IgE levels, the higher the serum zinc level in children. Our results suggest that hospitalised children are characterised by lower zinc levels, which may indicate its participation in the regulation of immune responses in patients with immune disorders.