OBJECTIVE To assess whether patients with psoriasis treated with tumor necrosis factor (TNF) inhibitors have a decreased risk of myocardial infarction (MI) compared with those not treated with TNF inhibitors. DESIGN Retrospective cohort study. SETTING Kaiser Permanente Southern California health plan. PATIENTS Patients with at least 3 International Classification of Diseases, Ninth Revision, Clinical Modification, codes for psoriasis (696.1) or psoriatic arthritis (696.0) (without antecedent MI) between January 1, 2004, and November 30, 2010. MAIN OUTCOME MEASURE Incident MI. RESULTS Of 8845 patients included, 1673 received a TNF inhibitor for at least 2 months (TNF inhibitor cohort), 2097 were TNF inhibitor naive and received other systemic agents or phototherapy (oral/phototherapy cohort), and 5075 were not treated with TNF inhibitors, other systemic therapies, or phototherapy (topical cohort). The median duration of follow-up was 4.3 years (interquartile range, 2.9, 5.5 years), and the median duration of TNF inhibitor therapy was 685 days (interquartile range, 215, 1312 days). After adjusting for MI risk factors, the TNF inhibitor cohort had a significantly lower hazard of MI compared with the topical cohort (adjusted hazard ratio, 0.50; 95% CI, 0.32-0.79). The incidence of MI in the TNF inhibitor, oral/phototherapy, and topical cohorts were 3.05, 3.85, and 6.73 per 1000 patient-years, respectively. CONCLUSIONS Use of TNF inhibitors for psoriasis was associated with a significant reduction in MI risk and incident rate compared with treatment with topical agents. Use of TNF inhibitors for psoriasis was associated with a non-statistically significant lower MI incident rate compared with treatment with oral agents/phototherapy.