Background: Greater platelet inhibition has resulted in a greater reduction of clinical outcomes in patients undergoing coronary stenting. Because of various limitations of traditional platelet function test, point-of-care (POC) platelet function tests have developed. However, there are limited data on correlations between the VerifyNow P2Y12 assay (VerifyNow) and traditional light transmittance aggregometry (LTA). Objectives and Methods: We compared VerifyNow values (PRU and % inhibition) with maximal and late platelet aggregation (AGGmax and AGGlate) induced by 5 and 20 ųM ADP in 554 patients undergoing stenting. We also could compare percent inhibition (PI) of PRU with PI of AGGmax and AGGlate in 150 patients. PI is defined as [(aggregation at baseline - aggregation at follow-up)/(aggregation at baseline)] X 100. Results: The 20 ųM ADP-induced AGG showed higher correlations with VerifyNow values compared with 5 ųM ADP-induced AGG (Table). In addition, AGGlate had a greater correlation with VerifyNow values than AGGmax. A stronger relationship was found between % inhibition and AGG than that of PRU and AGG. The optimal cut-off VerifyNow values for predicting high platelet reactivity (5 ųM ADP-induced AGGmax > 50%) was PRU ��� 240 (AUC 0.808, 95% CI 0.770 – 0.846, P < 0.001) and % inhibition ��� 21 (AUC 0.843, 95% CI 0.809 – 0.878, P < 0.001). PIs of PRU had acceptable and stronger correlations with PIs of 20 ųM ADP-induced AGG than those of 5 ųM ADP-induced AGG. Conclusions: Our results show a significant correlation between VerifyNow and LTA, which may suggest a substitutability of VerifyNow for assessing platelet inhibition in patients undergoing coronary stenting.