No nutritional index has been firmly established yet in patients with coronary artery disease (CAD). In this study, we propose a simple to calculate nutritional indicator in patients who underwent percutaneous coronary intervention (PCI) by using parameters routinely measured in CAD and evaluated its prognostic implication.This study is a retrospective observational analysis of a prospective database. The subjects were consecutive 3567 patients underwent their first PCI between 2000 and 2013 at Juntendo University Hospital in Tokyo. The median of the follow-up period was 6.3 years (range: 0-13.6 years). The novel nutritional index was calculated by the formula; Triglycerides (TG) × Total Cholesterol (TC) × Body Weight (BW) Index (TCBI) = TG × TC × BW / 1000 (TG and TC: mg/dl, and BW: kg).The Spearman non-parametric correlation coefficient between TCBI and the most often used conventional nutritional index, Geriatric Nutritional Risk Index (GNRI), was 0.355, indicating modest correlation. Moreover, Unadjusted Kaplan-Meier analysis showed higher all-cause mortality, cardiovascular mortality, and cancer mortality in patients with low TCBI. Consistently, elevation of TCBI was associated with reduced all-cause (hazard ratio: 0.86, 95%CI: 0.77-0.96, p < 0.001), cardiovascular (0.78, 0.66-0.92, p = 0.003), and cancer mortality (0.76, 0.58-0.99, p = 0.041) in patients after PCI by multivariate Cox proportional hazard analyses.TCBI, a novel and easy to calculate nutrition index, is a useful prognostic indicator in patients with CAD.