An issue of experimental studies is reviewed in view of their possibilities and limitations in assessing bioeffects and health risk of electromagnetic fields (EMFs). Investigations of bioeffets and their consequences are being performed at different levels of biological organization. Experimental studies involving cellular structures and animals lead mostly to the assessment of mechanisms of EMFs interaction and to the observation of possible bioeffects. To assess health risk of exposure to EMFs it is necessary to perform strudies involving human subjects (volunteers) or epidemiological studies targeted at specific human populations. The biological material applied in experiments appears to be a specific measure of the effect exerted by EMFs on the body, but as every measure, it has its own advantages and disadvantages and the obtained results may be burden with some errors, which should be analyzed during the interpretation of experimental study results. Med Pr 2008;59(1):79-86