Background: In the vast majority of psoriatic patients, psoriatic lesions are localised on the body as well as on the scalp. Therefore, safety data on the combined use of calcipotriol in lotion and calcipotriol in ointment are needed. Objective: This study investigated the effect of high-dose treatment with a combination of calcipotriol ointment and scalp solution on calcium metabolism, indices of bone turnover and PASI in patients with extensive psoriasis. Methods: Following a 2-week wash-out period, 88 patients were randomised to 4 weeks of treatment with either calcipotriol ointment/scalp solution (80–100 g/week and 30–50 ml/week, respectively; n = 41) or with a dithranol/tar regimen (n = 47). Patients were seen at weeks 1, 2 and 4 during treatment and 1 week following cessation of treatment. Results: No significant differences at the end of treatment were found between the 2 groups with respect to 24-hour urinary excretion of calcium (expressed as calcium/creatinine ratio), phosphate or pyridinoline, serum concentrations of calcium (albumin corrected), creatinine, phosphate, parathyroid hormone, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, osteocalcin, alkaline phosphatase (total and bone-specific iso-enzymes) or 1-collagen telopeptide. At the end of treatment, the psoriasis area and severity index had decreased by 57.4% in the calcipotriol group and by 36.1% in the dithranol/tar group (p = 0.004). Investigators’ and patients’ assessments of overall efficacy also favoured treatment with calcipotriol (p < 0.001). Conclusion: The combined use of calcipotriol ointment/scalp solution did not affect the indices of calcium metabolism or bone turnover and was significantly more effective than dithranol/tar in reducing disease severity and extent in patients with extensive psoriasis.