Because adalimumab and infliximab were approved in Japan for psoriasis treatment only 1 year ago, therapeutic efficacy of these agents is not well studied in a Japanese psoriasis population. Moreover, the evaluation of scalp psoriasis treated with biologics has never been reported in these subjects. In this study, 21 patients with moderate to severe plaque psoriasis were assigned to receive adalimumab 40 mg every other week with an initial loading dose of 80 mg (n = 11), or infliximab 5 mg/kg at weeks 0, 2, 6, 14 and 22 (n = 10). The treatment efficacy was evaluated by the proportion of patients who achieved at least 75% improvement in Psoriasis Area and Severity Index (PASI 75) and Psoriasis Scalp Severity Index score (PSSI 75) from baseline at weeks 4, 8, 16 and 24. A patient selection bias existed between the two groups in body surface area and PASI (44.0 ± 24.7 vs 30.2 ± 13.5, P = 0.12 and 22.2 ± 9.3 vs 15.6 ± 7.75, P = 0.09, respectively). At week 16, 81.8% of adalimumab-treated patients and 60.0% of infliximab-treated patients achieved PASI 75 response, but no statistically significant difference was found between these response rates. There was a tendency toward a reduced PSSI 75 response rate in the adalimumab-treated group compared to the infliximab-treated group (54.5% vs 90% at week 16, P = 0.15). In conclusion, both of the tumor necrosis factor-α inhibitors demonstrated good therapeutic response similar to that in the previously reported randomized controlled trials, without any severe adverse reactions. Treatment response in scalp lesions tended to be lower in adalimumab-treated patients, possibly because of delayed treatment onset of adalimumab.