The aim of the present study was to estimate the cuprum(Cu) level in blood serum in patients ill from measles in the acute period of the disease and three weeks after regression of clinical symptoms in comparison with the control group. The investigations included 26 patients aged 14-34, hospitalised due to measles in the Department of Infectious Diseases of the Medical University of Lublin. The analysed group included patients without coexisting diseases, in which clinical improvement after the carried out treatment was obtained. All the patients had Cu concentration in the blood serum twice determined during hospitalisation period and once during the period of convalescence. The control group included 24 healthy persons aged 15-19, who had Cu concentration in blood serum only once determined. The obtained in numbers data were subject to a statistical analysis. Both in the acute period of measles and during convalescence a statistically significantly higher Cu level in blood serum in comparison to the control group was observed.