Vascular inflammation is increased in patients with psoriasis. This randomized, double-blind, multicenter study evaluated the effects of tumor necrosis factor-α antagonist adalimumab on vascular inflammation in patients with psoriasis. A total of 107 patients were randomized (1:1) to receive adalimumab for 52 weeks or placebo for 16 weeks followed by adalimumab for 52 weeks. Vascular inflammation was assessed with positron emission tomography-computed tomography. There were no differences in the change from baseline in vessel wall target-to-background ratio (TBR) from the ascending aorta (primary endpoint) (adalimumab: TBR = 0.002, 95% confidence interval [CI] = –0.048 to 0.053; placebo: TBR = –0.002, 95% CI = –0.053 to 0.049; P = 0.916) and the carotids (adalimumab: TBR = 0.031, 95% CI = –0.005 to 0.066; placebo: TBR = 0.018, 95% CI = –0.019 to 0.055; P = 0.629) at week 16 between adalimumab and placebo.