Objectives To determine whether the dietary inflammatory index (DII) is associated with inflammatory or metabolic biomarkers and metabolic syndrome (MetSyn) among police officers. Methods Cross-sectional data from the Buffalo Cardio-Metabolic Occupational Police Stress study were derived from saliva and fasting blood samples, anthropometric measurements, long-term shiftwork histories, and demographic, stress/depression, and food frequency questionnaires. MetSyn was defined using standard criteria. Results Officers in DII quartiles 2–4 were more likely to exceed a 3.0mg/L threshold for C-reactive protein (odds ratio [OR]=1.88, 95% confidence interval [95%CI]=1.02–3.45; OR=2.17, 95%CI=1.19–3.95; OR=1.57, 95%CI=0.85–2.88, respectively) compared to quartile 1. The glucose intolerance component of MetSyn was more prevalent among officers in DII quartile 4 compared to quartile 1 (OR=2.03, 95%CI=1.08–3.82). Conclusions A pro-inflammatory diet was associated with elevated CRP and with the glucose intolerance component of the MetSyn.