Background Psoriasis contributes to unemployment, work impairment, missed workdays and substantial indirect costs due to lost productivity. Combination Cal/BD foam is the only topical that is approved for long-term maintenance treatment of plaque psoriasis for 52 weeks. This is the first known investigation of the effect of topical psoriasis therapy on productivity. Objective To examine the change in work productivity and activity impairment after 4 weeks of treatment with fixed-dose combination calcipotriol 50 mu g/g/betamethasone dipropionate 0.5 mg/g (Cal/BD) foam and observe long-term changes after 52 weeks of long-term management (proactive or reactive treatment). Methods This is a post-hoc analysis of the PSO-LONG trial - a phase 3, randomized, double-blind, vehicle-controlled, parallel group, international multi-centre trial of treatment with combination Cal/BD foam. Work and activity impairment due to psoriasis were assessed by the Dermatology Life Quality Index (DLQI) and the Work Productivity and Activity Impairment Psoriasis (WPAI:PSO) questionnaire at baseline, week 4, week 28 and week 56. The improvement in hours of work productivity was translated into monthly and annual indirect cost savings estimates for patients in Italy, Sweden, United Kingdom, Canada and Germany. Results Using fixed-dose combination Cal/BD foam for four weeks significantly reduced psoriasis-related work presenteeism, total work productivity impairment (TWPI) and total activity impairment (TAI) over 56 weeks, with significant improvements observed as early as 4 weeks after the baseline visit. The proportion of patients reporting impact on work productivity (as measured by presenteeism and TWPI) and activity impairment (as measured by both DLQI-Q7b and TAI) also decreased. Conclusion Fixed-dose combination Cal/BD foam used for long-term management of psoriasis significantly reduces psoriasis-related work productivity and activity impairment which may result in substantial indirect cost savings.