BACKGROUND Little information is known about telomerase expression in the chronic benign hyperproliferative skin disease, psoriasis. Further studies are still required to investigate its usefulness as a biomarker of this skin disorder. OBJECTIVE To investigate the expression of human telomerase reverse transcriptase (hTERT) in psoriatic lesional skin and its relation to disease severity. METHODS The levels of hTERT-mRNA were quantified using real time RT-PCR in lesional versus nonlesional skin specimens from 24 psoriatic patients. RESULTS The expression of hTERT was detected in 16 psoriatic lesional specimens (66.7%), but in none of the normal skin. There was no relation between hTERT expression level and age of the patient or the duration of the disease. Among hTERT-positive patients, a significant positive correlation was observed between hTERT-mRNA levels and both the Psoriasis Area-and-Severity Index (PASI) and scaling scores (p = 0.012 & p = 0.006, respectively). CONCLUSIONS Telomerase mRNA is detectable in lesional skin of most psoriatic patients and correlates with the severity of the disease and the rate of epidermal proliferation.