Many physiological functions are under the control of a central biological clock regulated by the circadian rhythm, which follows the successive night and day cycles. At a molecular level the circadian clock consists of an auto-regulatory gene expression feedback loop driven by oscillating expression of a family of transcription factors called clock genes (Clock, Bmal, Per, Cry). The skin is the first barrier of the body against environmental aggressions such as UVs, pollution, but is also submitted to internal cellular stresses that varies a lot depending on the time of the day, therefore it is consistent that skin functions and mechanisms are monitored by circadian clock.The behavior of epidermal keratinocytes has been shown to follow a circadian rhythm, nevertheless the link between circadian rhythmicity alteration and skin integrity is largely unexplored. Besides, some recent evidences, in mice, have linked circadian rhythm abnormalities (Bmal1 KO) and skin aging. Unfortunately, the role of period genes and skin physiology and in particular skin aging was not investigated. For this purpose, we performed keratinocytes knocked down for PER2, PER3 or both expressions using small-hairpin RNA technology to generate a silenced reconstructed human epidermis. We showed that PER3 dramatic decreased expression (91% depletion) impairs the epidermal tissue morphology with a reduced number of keratinocyte layers, a reduced stratum corneum thickness and reduced keratohyalin granules. In accordance, the expression of filaggrin, a major structural protein involved in terminal differentiation and skin barrier function is altered. On the other hand, PER2 impaired expression (79% depletion) doesn’t show alteration on the same parameters. Epidermis with both PER2 and PER3 impaired expression presented a similar phenotype than PER3 knock-down one. We demonstrated that PER3 plays a role in epidermal homeostasis related to barrier function maintenance and aging features.