Psoriasis is a chronic inflammatory skin disorder clinically characterized by erythematous, sharply demarcated papules and rounded plaques covered by silvery micaceous scale. While the exact causes of psoriasis have yet to be discovered, the immune system and genetics are known to play major roles in its development. Many external factors including infections, stress and medications may exacerbate psoriasis. Some of the most common medications know to trigger or worsen existing psoriasis include lithium, gold salts, beta blockers and antimalarials. Exacerbation of psoriasis due to the following medications has also been observed: adrenergic antagonists, interferon, gemfibrozil, iodine, digoxin and chlonidine. Having reviewed a variety of cases, we observed a relationship between certain medications and documented their involvement in exacerbating or inducing psoriasis.