Objective To investigate and compare the effect of radio-frequency (RF) field exposure on expression of heat shock proteins (Hsps) in three human glioma cell lines (MO54, A172, and T98). Methods Cells were exposed to sham or 1950 MHz continuous-wave for 1 h. Specific absorption rates (SARs) were 1 and 10 W/kg. Localization and expression of Hsp27 and phosphorylated Hsp27 ((78) Ser) (p-Hsp27) were examined by immunocytochemistry. Expression levels of Hsp27, p-Hs27, and Hsp70 were determined by Western blotting. Results The Hsp27 was primarily located within the cytoplasm, p-Hsp27 in both cytoplasm and nuclei of MO54, A172, and T98 cells. RF field exposure did not affect the distribution or expression of Hsp27. In addition, Western blotting showed no significant differences in protein expression of Hsp27 or Hsp70 between sham- and RF field-exposed cells at a SAR of 1 W/kg and 10 W/kg for 1 h in three cells lines. Exposure to RF field at a SAR of 10 W/kg for 1 h slightly decreased the protein level of phosphorylated Hsp27 in MO54 cells. Conclusion The 1950 MHz RF field has only little or no apparent effect on Hsp70 and Hsp27 expression in MO54, A172, and T98 cells. Objective To investigate and compare the effect of radio-frequency (RF) field exposure on expression of heat shock proteins (Hsps) in three human glioma cell lines (MO54, A172, and T98). Methods Cells were exposed to sham or 1950 MHz continuous Localization and expression of Hsp27 and phosphorylated Hsp27 ((78) Ser) (p-Hsp27) were examined by immunocytochemistry. Expression levels of Hsp27, p -Hs27, and Hsp70 were determined by Western blotting. Results The Hsp27 was primarily located within the cytoplasm, p-Hsp27 in both cytoplasm and nuclei of MO54, A172, and T98 cells. RF field exposure did not affect the distribution or expression of Hsp27 . In addition, Western blotting showed no significant differences in protein expression of Hsp27 or Hsp70 between sham- and RF field-exposed cells at a SAR of 1 W / kg and 10 W / kg for 1 h in three cells lines. Exposure to RF field at a SAR of 10 W / kg for 1 h slightly decreased the pro tein level of phosphorylated Hsp27 in MO54 cells. Conclusion The 1950 MHz RF field has only little or no apparent effect on Hsp70 and Hsp27 expression in MO54, A172, and T98 cells.