This post-approval, open-label trial (n = 1266) assessed the efficacy of efalizumab, administered in accordance with the European label at that time, in patients with concomitant nail, scalp or palmoplantar psoriasis. Patients received subcutaneous efalizumab 1.0 mg/kg weekly for up to 20 weeks. By Week 12, an improvement from baseline of 50% or more was observed in 21.4% (181/844) of patients with nail psoriasis, 62.4% (718/1150) of patients with scalp psoriasis, and 51.4% (127/247) of patients with palmoplantar psoriasis. Quality of life improved throughout the trial, with a 50% median improvement in DLQI score after 12 weeks of treatment. Efalizumab showed promising efficacy in the treatment of nail, scalp and palmoplantar psoriasis, which was reflected in improvements in quality of life.