Paced QRS morphology may vary during left bundle branch area pacing (LBBAP) as per the pacing location. It remains unclear whether electrocardiographic changes observed during LBBAP can predict clinical outcomes. To assess correlation between characteristics of paced QRS on electrocardiogram and clinical outcomes in heart failure (HF) patients with non-ischemic cardiomyopathy. Of 79 consecutive HF patients receiving LBBAP, 59 patients were included in this prospective study after exclusions. LBBAP was performed using Medtronic 3830 lead. Patients were categorized into various groups based on paced QRS morphology in lead V1 (qR and Qr), QRS axis (normal, left or right) and V6 R wave peak time (RWPT, ≤80 or >80 ms) to compare echocardiographic outcomes. RWPT was significantly shorter (75.7±17.5 vs 85.3±11.3 ms, P=0.014), transition during threshold test more commonly observed (81.5% vs 53%, P=0.02) and improvement in left ventricular ejection fraction (LVEF) was significantly greater in qR group (21.4±6.4 vs 16.4±8.3%, P=0.013) compared to Qr group. RWPT or LVEF did not differ in patients with different paced QRS axis (P>0.05). While qR morphology and presence of transition during threshold test independently predicted LVEF improvement, RWPT lacked predictive value. Non-responders had greater incidence of loss of 'R' prime (P=0.009) and prolonged RWPT (P=0.003) on follow up compared to average and super-responders. Paced qR morphology and transition during threshold test predicted greater improvement in LVEF while RWPT lacked predictive value. Loss of terminal 'R' in lead V1 and prolongation of RWPT on follow up prognosticated non-response to LBBAP.