Background. Globin chain synthesis (GCS) analysis is used in the diagnosis of thalassemia. However, the wide reference range limits its use as a decisive diagnostic tool. It has been shown that α and β globin mRNA increase through stimulation of cells by interleukin-3 (IL-3). Therefore, this study investigates the relationship between plasma IL-3 and the β/α globin ratio. Methods. Blood samples were collected from 32 healthy participants on two occasions one month apart. GCS analysis, real-time PCR, and ELISA tests were conducted to determine the β/α globin ratio, globin mRNA expression and stability rate, and IL-3 levels. Results. On the basis of IL-3 levels, the participants were divided in two groups. One group included participants who showed a significant increase in IL-3 as indicated by a significant rise in mean values of α, β, and γ globin mRNA, α and β globin, RBC, and hemoglobin. The other group included participants who showed no difference in IL-3 levels with no significant variations in the above-mentioned parameters. Conclusion. The results of this study indicate that IL-3 has an equivalent positive effect on α and β globin chain synthesis. Therefore, IL-3 levels do not explain the wide reference range of the α/β globin ratio.