Introduction: Psoriasis is chronic inflammatory skin disease, in which activated T cells are strongly implicated in the pathophysiological processes; it is characterized by excessively increased keratinocyte proliferation. Human telomerase enzyme, extends chromosome ends with (TTAGGG)n sequences, and thus plays a key role in maintaining telomere length which is necessary for long-term cell proliferation Methods: This study compromised 20 patients and 10 controls. All cases were subjected to complete history taking, clinical examination (including PASI score), and skin biopsy. CBC, liver and kidney functions, abdominal sonar were done to exclude malignancy. A 3ml blood sample was obtained from each of 20 patients and 10 controls, collected in heparinized tubes, lymphocytes were separated, then telomerase activity was measured by PCR ELISA technique. Results: Results showed significant increase of telomerase activity in psoriatic blood in comparison to low levels in blood of controls, with no relation to age, duration, family history, or severity of the disease (measured by PASI score). Conclusion: Increased telomerase activity has an important role in psoriasis as a hyperproliferative skin disease either as a cause or as a result.