The increasing public concern regarding the potential health risks of exposure to electromagnetic fields (EMFs) has led to intensive research in this area. However, it remains unclear whether potential pro?oncogenic effects may be caused by power frequency EMF (PFEMF) exposure. To address the associated risk factors, the present study exposed 4?week old Balb/c mice to 0, 0.1, 0.5 and 2.5?mT of constant 50?Hz Helmholtz coil?type PFEMF for 90?days to explore the circulating chemokine indicators that may be associated with inflammation or cancer. No measurable weight difference existed between the control and PFEMF?exposure groups; however, the Luminex assay clearly demonstrated differentially responsive profiles of circulating chemokines upon PFEMF treatment. Monocyte chemoattractant protein (MCP)?3, macrophage inflammatory protein (MIP)?1α, MIP?1β and MIP?2 levels in serum were not significantly altered by PFEMF during the 3?month exposure period; however, the circulating levels of other chemokines including IP?10, GROα, RANTES, EOTAXIN?1 and MCP?1 exhibited significant changes upon treatment. Among the responsive chemokines, EOTAXIN?1 and MCP?1 were significantly increased by 0.5?mT of PFEMF treatment, which may support their use as indicators of PFEMF exposure. This novel finding highlights the potential pro?inflammatory nature of power frequency, which may shed light on the mechanisms underlying PFEMF?induced diseases, including cancer.