Introduction & Objective: The use of computers and monitors (displays) has been developed due to their increasing capabilities. The presence of electromagnetic fields, infrared and ul-traviolet radiations has been proven around the display, which all of them have adverse ef-fects on human health. Therefore, this study was conducted to survey and compare the mentioned variables around the displays.

 Material & Methods: The present descriptive–analytical study was accomplished in Hamadan university of medical sciences in 2011. The statistical sample included 46 LCD and 50 CRT devices selected by simple random sampling. In order to assay the electric and magnetic fields, the HI-3604 device and for measuring the IR and UV rays, Hanger device was used.

Results: The magnetic field in the CRT display was higher than the LCD display. Also the magnetic field of the front of the display was more than back position in the both displays (P=0.000). The electric field in the nearest distance of the display was higher in CRT than LCD (P=0.000). In 30 cm distances of CRT and LCD displays, 96% and 8.3% of the sam-ples had magnetic field more than TCO standard, respectively.

Conclusions: The current finding demonstrated that LCD displays radiate much lower amount of magnetic field, IR and UV rays than CRT displays. Life extension of the system has a great influence on the production of electromagnetic fields.