Nail psoriasis is common among patients with plaque psoriasis or psoriatic arthritis and has a detrimental effect on quality of life. However, there are currently no standardized therapeutic regimens for nail psoriasis. Traditional treatments for nail psoriasis, which include topical, intralesional, and oral therapies, may be time-consuming, painful, or unsafe when administered long term. Biologic therapies have demonstrated efficacy for plaque psoriasis and psoriatic arthritis; these therapies may be particularly promising for the treatment of nail psoriasis as both groups of patients have an elevated incidence of nail dystrophy. The biologic therapies adalimumab, alefacept, efalizumab, etanercept, and infliximab have demonstrated clinically important nail psoriasis improvements using the Nail Psoriasis Severity Index, a helpful tool that, upon validation, will allow comparison across treatments and trials. Large-scale, long-term trials using standardized outcome measures are needed to further evaluate biologic therapies for the treatment of nail psoriasis.