OBJECTIVES To assess the cost differences between adalimumab and etanercept for chronic plaque psoriasis. METHODS A model was constructed to compare the drug acquisition costs for adalimumab and etanercept for chronic plaque psoriasis for a hypothetical primary care trust. The number of patients eligible for anti-TNF treatment was taken from published sources. Patients were assumed to receive either etanercept intermittently, mixed intermittent and continuous, continuous, or continuous adalimumab. Market research demonstrated that about 36% of patients are likely to receive continuous etanercept. Adalimumab, in contrast can not be used intermittently. Costs were estimated from a UK payer perspective. The time horizon is three years. RESULTS We estimated that the hypothetical PCT would cover 250,000 people, which is approximately the average size of a PCT in the UK. Of these 195,000 would be ≥ 18 years of age. thirty-five patients would meet the criteria for either adalimumab or etanercept. Providing that all patients would receive intermittent etanercept this would cost the NHS GBP 722,190, if 36% receive continuous etanercept and the rest intermittent etanercept it would cost GBP 816,453, whilst if all patients would receive continuous etanercept it would cost GBP 975,975. All patients receiving continuous adalimumab would cost GBP 1,001,000. CONCLUSIONS Our model found potential for cost savings for PCTs from using etanercept instead of adalimumab, within the recommended patient groups for chronic plaque psoriasis. Savings will be increasingly important if the proportion of eligible patients who receive treatment increases from the current level.