Zinc concentrations in hair and urine were measured in groups of children varying in one condition - short stature, or after prolonged upper respiratory infection, or during non-infectious diarrhea, or while on chemotherapy for acute lymphatic leukaemia and in healthy controls. As compared with controls, hair zinc was significantly low after respiratory infection (p less than 0.0001) and high in short stature (p less than 0.01). Urinary zinc was increased during initial chemotherapy (p less than 0.001) and diarrhea (p less than 0.02). It is shown that zinc deficiency occurs in one of the common symptoms in paediatric medicine, namely upper respiratory tract infection. The high overlap (34-88%) proves hair and urine zinc to be of no use for reliable individual diagnostic statements.