The mobile phones radiate electromagnetic energy which is partly absorbed into the tissues in the vicinity of the phone. The minor heating, in maximum up to 0.3 degrees C, may cause some alterations in the expression of genes and proteins similar to physiological response to other stimuli. Biophysical studies at the cellular and molecular level have not revealed any well established interaction mechanism, through which mobile phone radiation could induce toxic effects below the thermal effect level. Research results on various biological effects in vitro and in vivo are continuously published but there is no consistent evidence on well established harmful effects. The mobile phone radiation is not carcinogenic for experimental animals or genotoxic for cells. According to epidemiological studies and psychophysiological brain function studies the use of mobile phones does not seem to increase the risk of tumors in the head and brain or disturb the function of central nervous system. However, there is a need for more research on the long-term effects of mobile phone radiation particularly on children.