Ek kustha is a type of kshudra kustha described in different Ayurvedic classics. It is a vata-kaphaj disorder. The clinical symptom of Ek kustha described in Ayurveda resembles with the clinical symptom of Psoriasis. The clinical feature of Ek kustha described by Kashyap represents remission, relapse and seasonal variation, which are present in Psoriasis. In modern medicine there is no definite treatment for this disease. The medicines, which are available to treat the disease, are not very effective and cannot be used for long-term management because of their local and systemic side effect as well as toxicity. Medicines, which are used in Ayurveda, are safe and being practiced since thousands of year. A large number of drugs and measures are described in Ayurveda for the treatment of Kustha. This study was designed to access the anti-inflammatory activity of Leech Therapy in the treatment psoriasis (Ek kustha). The study was randomized open phase clinical trial. The patients of age group 18 to 60 were selected on the basis of Ayurvedic signs and symptoms of Ek kustha. Observations were recorded for sharply defined erythemosquamous lesions varying in size; presence of erythema, scaling and induration in the lesions; surface consists of non-coherent scales; positive Auspitz sign – (Bleeding occurs after scratching of scales); positive onion peeling sign/candle grease sign (after scratching the scales fall like peels of onion). Since the assessment criteria was Quantitative, paired 't' test was applied. In the current study the treatment was found significantly effective in treating psoriasis. So, we can conclude that leech therapy is effective in the treatment of psoriasis.