The aim of this research was to determine if the age of healthy subjects older than 40 years of age has an influence on the concentration of β2‐microglobulin in the serum of subjects of different populations. We examined the values of β2‐microglobulin in the serum of 51 healthy subjects aged 40–86 years using the microparticle enzyme immunoassay AxSYM β2‐microglobulin test. The reference values of β2‐microglobulin according to the nonparametric statistical method is 0.95–2.73 mg/L. A correlation was found between β2‐microglobulin and age: 40–50 years (0.94–1.54 mg/L), 51–65 years (0.96–2.62 mg/L), and >65 years (1.13–2.84 mg/L). There was no significant statistical difference of β2‐microglobulin between genders (P > 0.05); however, there was a statistically significant difference between the concentration of β2‐microglobulin and the subjects' age. (Spearman's rank correlation coefficient ρ = 0.66; P < 0.01). A direct correlation between age and the concentration of β2‐microglobulin was observed. This research is a contribution to determining reference values of β2‐microglobulin in subjects of different populations.