The HAT2CH2 score [Hypertension (1 point), Age > 75 years (1 point), Stroke/Transient ischemic attack (2 points), Chronic obstructive pulmonary disease (1 point), and Heart failure (2 points)] was originally developed to predict the occurrence of new-onset atrial fibrillation. The aim of the present study was to examine whether this score could predict the development of no-reflow phenomenon (NR) in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (pPCI). Patients (n = 1552) with STEMI were consecutively enrolled in this single-center retrospective study. The SYNTAX score (SXscore) and HAT2CH2 score were calculated. The presence of thrombolysis in myocardial infarction (TIMI) score ≤2, without significant residual stenosis and mechanical obstruction, indicated the presence of NR. The HAT2CH2 score was significantly higher in the NR (+) group compared with the NR (−) group [2.29 ± 1.43 vs 1.46 ± 1.24, p < .001]. In multivariable logistic regression analysis, the HAT2CH2 score [OR = 1.585, p < .001] and SXscore [OR = 1.028, p = .017] were found to be independent predictors of NR. Receiver operating characteristic curve analysis showed that the HAT2CH2 score with a cutoff value of >2 determined NR, with 50.2% sensitivity and 79.4% specificity (AUC = .669, p < .001). In conclusion, the HAT2CH2 score may facilitate risk stratification in estimating NR in STEMI patients undergoing pPCI.