Psoriasis is a chronic inflammatory skin disease that is mediated by T-cell dependent immune responses. Cyclosporine, a general suppressor of T cells, has been used to treat psoriasis. Biologics targeting various immuneassociated cytokines are also currently in use or are under development. TNF-α inhibitors are successful examples of such biologics. More recent biologics have targeted a psoriasis-specific immune pathway, IL-23/Th17. The IL-12/23p40 inhibitor, ustekinumab, as well as the IL-17 antagonists secukinumab, ixekizumab, and brodalumab, have proven to be highly effective for psoriasis and have been approved for clinical use. This review discusses the treatment of psoriasis with immunosuppressants in the context of the current understanding of psoriasis pathophysiology.