Hair disorders that have been described in association with pegylated interferon-ribavirin combination treatment include canities, hypertrichosis, telogen effluvium, and the most common cutaneous side-effect by far, alopecia. Alopecia is a heterogeneous disease characterized by hair loss on the scalp or any hair-bearing surface with a wide range of clinical presentations, from a single patch of hair loss to complete loss of hair on the entire body (alopecia universalis). Although some cases of reversible alopecia universalis associated with pegylated interferon-ribavirin combination therapy have been reported in the published work, irreversible alopecia universalis has not yet been reported in relation to pegylated interferon and ribavirin combination treatment. For the first time, we report a case of irreversible alopecia universalis during pegylated interferon-ribavirin combination therapy in a man infected with hepatitis C virus in the absence of clinical or biochemical evidence of immunological disorders or thyroid dysfunction at any time before, during or after antiviral therapy.