The impact of electromagnetic field (EMF) on humans has been described in numerous studies, but many questions are still unanswered. The aim of the experiment described in this study was to evaluate the effect of EMF on the viability of human fibroblast BJ in vitro and the percentage of cells in different phases of the cell cycle (G1/G0, S, G2/M) after 2 hours of exposure to sinusoidal continuous and pulsed EMFs with frequency of 5 Hz, 60 Hz and 120 Hz at a magnetic induction of 2,5 mT. The viability of BJ cells exposed to an EMF was estimated immediately after completion of exposure and after 24 hours. Metabolic activity of cells was assessed by MTT assay and compared to a control culture not exposed to EMFs. Cell cycle analysis was performed by BrdU incorporation. The analysis of the viability demonstrated significant differences in field efficiency, depending on its nature. Exposure of cells to pulse EMFs resulted in a decrease in their viability for each of the analyzed frequencies. Reduced viability was maintained for a further 24 hours after the end of exposure of cells to pulsed EMF. In the case of continuous field, reduced BJ cell viability was observed only at the highest applied frequency - 120Hz, and this effect maintained for the next 24 hours. Although there was no significant effect on cell viability (metabolic activity) of cells immediately after exposure to continuous EMF with a frequency of 5Hz, a significant increase was observed after 24 hours of incubation.