BACKGROUND: Psoriasis of the scalp is a very common disease, cosmetically disturbing and therapeutically difficult to manage. OBJECTIVE: The aim of our study was to investigate the efficacy, safety and cosmetic acceptance of calcipotriol solution in a large number of patients with mild to moderate scalp psoriasis and to compare this treatment with previous therapies used. METHODS: In this multicentre prospective observational cohort study 3,396 patients were treated with calcipotriol solution (50 microg/ml) twice daily over an 8-week period either alone or in combination with other treatments. The psoriasis scalp severity index (PSSI) and investigator/patient global assessment were used for the evaluation of clinical response. RESULTS: All psoriasis severity parameters measured were reduced with a significant decrease in PSSI scores from 18.4 to 5.6 after 8 weeks of therapy (p < 0.001). About 80% of the patients showed very good or good clinical improvement. Combination of calcipotriol solution with other treatment modalities e.g. corticosteroids or salicylic acid, showed an increased treatment response. In only 2.4% of the patients side effects occurred (e.g. irritation). CONCLUSION: Calcipotriol solution is an effective, safe, well-tolerated and cosmetically acceptable treatment modality. By patients and physicians, this treatment was found to be a valuable supplement to previously available and established treatments for scalp psoriasis.