Ostraceous psoriasis is a rare variant of psoriasis, characterized by severe hyperkeratotic lesions resembling an oyster shell. Adalimumab is a biological agent that antagonizes tumor necrosis factor (TNF) and is used clinically in plaque psoriasis. Some medications such as lithium carbonate (LC) may aggravate or trigger psoriasis. Here, we describe a case of generalized ostraceous psoriasis associated with lithium carbonate, whose lesions completely improved after discontinuing lithium carbonate and using adalimumab.