The acute toxicity of a multimineral complex for the prevention and correction of regional microelementosis in residents of northern territories, containing calcium, magnesium, zinc, and selenium was studied. The mineral complex was developed based on the Republic of Karelia inhabitants elemental portrait. 80 Wistar rats (females and males) were used for the experiment. The animals were divided into four equal groups: control and experimental groups, which received once the mineral complex in ten-fold, thirty-fold, fifty-fold average effective doses. The mineral complex was administered orally with food individually to each experimental animal. During 2 weeks of observation not a single death was recorded. All animals were clinically healthy, behavior and general condition in all study groups were similar and corresponded to gender and age characteristics. LD50 and LD100 values for male and female rats were not possible to determine. There were no differences in the dynamics of body weight gain in the experimental and control animal groups. Daily diuresis assessment and urine biochemical analysis did not reveal a negative effect of the mineral complex on renal function. After 2 weeks of observation all animals were euthanized, aninternal organs macroscopic analysis and a biochemical blood test were performed. No internal organs pathological changes in all studied groups were observed. Assessment of biochemical blood parameters did not reveal any negative changes in liver and kidney function in rats compared to the control. According to the results obtained, the mineral complex can be classified as hazard class 4 (low-hazard) (GOST 12.1.007-76).