Objective: To investigate the association of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) with the long-term prognosis of ST-elevation myocardial infarction (STEMI) patients and to determine whether the combination of obesity indices can be used for risk stratification. Method: A multifactorial Cox regression analysis was performed using 3-year follow-up data from 220 STEMI patients to explore the relationship between obesity indicators and major adverse cardiovascular events (MACEs). The incidence of MACEs was also compared by combining BMI and WHtR. Results: WC was found to reduce the risk of MACEs within 25 months after myocardial infarction [hazard ratio (HR) = 0.95, 95% confidence interval (CI) = 0.92–0.98, P < 0.001]. However, this effect was not significant beyond 25 months (HR = 0.98, 95% CI = 0.97–1.07, P = 0.49). Neither BMI nor WHtR were significantly associated with the risk of MACEs. The incidence of MACEs was highest in patients with low body weight (BMI < 18.5 kg/m²) and WHtR > 0.5, and lowest in obese patients (BMI ≥ 28 kg/m²) with WHtR > 0.5. Conclusions: BMI, WC, and WHtR were not significantly associated with the long-term prognosis of STEMI patients. However, the combination of BMI and WHtR can be useful for further stratifying patient risk.