This study aimed to investigate if 1800 MHz RF-EMFs can induce reactive oxygen species release and/or heat shock protein 70 expression in human blood cells. Cells were exposed to CW or GSM-DTX and GSM-Talk signals at 2 W/kg for 30 or 45 min of continuous or intermittent exposure. Chemical- and heat treatment were used as positive controls respectively. The results demonstrated that RF-EMF exposure of human monocytes and lymphocytes, using different RF signals and exposure times, does not have any activating capacity to induce ROS release or Hsp70 expression. One exception: continuous and intermittent GSM-DTX exposure of human monocytes induced a decrease in ROS level during sham exposure, whereas human lymphocytes did not respond in the same manner.