Despite their benefits, technological devices such as cell phones may also have deleterious effects on human health. Considerable debate continues concerning the effects of the electromagnetic field (EMF) emitted during cell phone use on human health. We investigated the effects of exposure to 900 megahertz (MHz) EMF during mid to late adolescence on the rat liver. Control (ContGr), sham (ShmGr) and EMF (EMFGr) groups of female rats were established. We exposed the EMFGr rats daily to 900 MHz EMF on postnatal days 35-59. ShmGr rats underwent sham procedures. No procedure was performed on ContGr rats. Rats were sacrificed on postnatal day 60 and the livers were extracted. One part of the liver was stained with Masson's trichrome or hematoxylin and eosin. The remaining tissue was used to measure oxidative stress markers including malondialdehyde, glutathione, catalase, superoxide dismutase, 8-hydroxydeoxyguanosine (8-OHdG) and nitrotyrosine. Total antioxidant status and total oxidant status were used to calculate the oxidative stress index. We found normal hepatic morphology in the ContGr and ShmGr groups. The EMFGr group exhibited occasional irregularities in the radial arrangement of hepatocytes, cytoplasmic vacuolization, hemorrhage, sinusoid expansion, hepatocyte morphology and edema. Biochemical analysis revealed that 8-OHdG and SOD levels in EMFGr decreased significantly compared to the ContGr and ShmGr groups. Exposure to a continuous 900 MHz EMF for 1 h daily during mid to late adolescence may cause histopathological and biochemical alterations in hepatic tissue.