The determination of the concentration of biolelements in hair is approached as a non-invasive method of measurement of the actual state of nutrition with those compounds within the period of approximately two months preceding the study. The objective of the study was the determination whether there is a relationship between the concentration of selected biolelements in hair of pre-school children from Cracow, the value of the BMI index and percentage of the fatty tissue in the total body mass. A complex study of the mode of nutrition and nutritional status covered 74 pre-school children aged 4.5-7 years from various quarters of Cracow. Nutritional status was assessed by the values of the BMI index and fat tissue mass. The concentration in hair of the following elements: ferrum, copper, calcium, magnesium, sodium, potassium, zinc, cobalt, and manganese was determined by the method of atomic absorption spectrophotometry with the use of Perkin-Elmer AAnalyst 800 spectrophotometer. No significant relationship was observed between the concentration of Ca, Se, Cu, Fe, Zn, and Co in hair of the children examined and their nutritional status. Excess and deficiency of the bioelements analysed in hair were noted both in underweight and overweight children, and those with excessive weight (over 95 centile) and with fat tissue mass below 5th centile.