Background: Expansion of the use of magnetic fields in metals, mining, transport, research, and medicine industries has led to a discussion about the effects of magnetic fields and whether their strength is negligible. The aim of this study was to investigate the effects of magnetic field on the viability and proliferation rate of HeLa cells. Materials and Methods: We studied the effects of magnetic field on the viability, proliferation rate and membrane lipid peroxidation of cells, thus, HeLa cells (cancer cells) and human fibroblast cells (normal cells) were used. Initially, the cells were cultured in DMEM and to determine the impact of the magnetic field, the cells were treated with magnetic field at 4 specific intensity levels (0, 7, 14 and 21 mT) and 2 exposure times (24 h and 48 h). The viability percentage and inhibition of cell proliferation were calculated by MTT assay and Trypan blue staining, respectively. Results: Lipid peroxidation of the cell membrane was examined by malondialdehyde (MDA) method. As the intensity and exposure time of the static magnetic field (SMF) increased, the viability percentage and proliferation rate decreased and the lipid peroxidation levels increased in the Hela cells. Conclusion: In this study, we have shown the anticancer effects of static magnetic field and propose a suitable intensity range that can be effective for the treatment of cancer.