Background: An elevated homocysteine level is an independent risk factor for cardiovascular disorders. Psoriatic patients have an increased risk of cardiovascular diseases; In addition, hyperhomocysteinemia is a complication of methotrexate treatment. We undertook a study to evaluate the plasma levels of homocysteine, vitamin B12 and folate in patients with psoriasis before and after short-term low-dose methotrexate treatment. Methods: Twenty six patients with psoriasis were recruited. The plasma levels of homocysteine, vitamin B12 and folate were evaluated before and 8 weeks after methotrexate therapy (in the peak of methotrexate effect). Results: No significant difference was found between the plasma profile of homocysteine, vitamin B12 and folate before and after methotrexate treatment. Conclusion: In the short-term treatment of psoriasis, methotrexate does not increase homocysteine level.