Background: Cellular senescence is one of the major factors contributing to the aging process. Photobiomodulation (PBM) is known to trigger an array of cellular responses, but there are no data on how it affects the process of cellular senescence. In this study, we analyze the effect of PBM on the cellular senescence and telomere dynamics. Methods: Human dermal fibroblasts were irradiated by a panel of light-emitting diodes with 590 nm and dose 30 J/cm2 accumulated over 1200 sec repeated in 4-day cycle within 40 days. After the last cycle of PBM treatment, the difference in number of senescent cells between PBM treated groups end nontreated control groups was measured by senescent sensitive β-galactosidase assay, and the difference in average telomere length between the experimental end control groups was analyzed using relative human telomere length quantitative Polymerase Chain Reaction (qPCR) assay.