Objectives: The aim of this study was to investigate the response of human skeletal muscle myoblasts to therapeutic doses of X-irradiation. Methods: Myoblasts was established via skeletal muscle biopsies which irradiated in vitro by x-ray at doses 3, 5 and 7 Gy. Two effects of radiation were measured (acute effect after 24h and long term effect after 72h). Acute effect was monitored by interleukin-6 release, while long term effect was monitored by measuring the proliferation capacity and cell death. Results: When comparing the non-irradiated control and cells processed with inhibitor of cell proliferation Ara C, myoblast proliferation reduced in 72h post-radiation, this change was significant with increasing doses. Post-irradiation myoblast survival determined by measurement of released LDH enzyme activity showed increased activity after exposure to x-rays. The acute reaction of myoblasts to lower doses of irradiation (3 and 5 Gy.) was reduced secretion of constitutive interleukin-6. Conclusion: The current study approved that there was positive response of human skeletal muscle myoblasts to therapeutic doses of X-irradiation..