Adverse effects may occur in 10.4% of patients receiving terbinafine therapy, with cutaneous reactions in 2.7%. We describe the development of psoriasis in four patients who took oral terbinafine. Two patients had plaque-type psoriasis that flared 12 and 17 days, respectively, after starting terbinafine. Another patient developed pustular-type psoriasis de novo after 27 days of terbinafine therapy. The fourth patient was a psoriatic with stable plaque disease who experienced a pustular flare after taking terbinafine for 21 days. We are aware of only one report in the literature in which a patient developed pustular psoriasis de novo after 5 days of terbinafine therapy. In all patients the psoriasis cleared or lessened after discontinuation of terbinafine and institution of antipsoriatic therapy.