Background: ACS is a life threatening manifestation of CAD. It warrants an early risk stratification and timely intervention. Recently, Haematological indices, have gained attention because of their significant associations in predicting outcomes of CAD. We carried out a prospective cross-sectional study among ACS patients to find the association of Red Cell Distribution Width (RDW), Haemoglobin Corrected RDW (HbCRDW), Red Cell Width Volume Index (RWVI), Neutrophil/Lymphocyte Ratio (NLR) and Platelet Distribution Width (PDW) with in-hospital Major Cardiac Adverse Events (MACEs) (Recurrent Angina, Clinical LVF, LV Dysfunction by Echocardiogram, Arrhythmias and Death). Methods: 100 ACS patients admitted in our hospital were enrolled for the study. The significance of association between the haematological parameters with the MACEs were found using Fisher Exact Test. Results: Frequency of occurrence of In- hospital MACEs were 17% Recurrent Angina, 42% Clinical LVF, 57% LV Dysfunction, 18% Arrhythmias and 10% Mortality. Using Fisher-Exact test, although indices had no significance with mortality, RDW (>15%) had a significant association with Recurrent Angina (P=0.012) and LV Dysfunction (P=0.09). Higher tertiles of HbCRDW & RWVI had significance in predicting Recurrent Angina with P values of 0.013&0.043 respectively. Higher tertiles of NLR (>3.75) was significant in predicting Clinical LVF (P=0.086) and Arrhythmias (P=0.080). Conclusion: RDW and its derived indices HbCRDW, RWVI are strong predictors of in-hospital Recurrent Angina among ACS patients. In addition, Higher values of RDW are also useful in predicting LV dysfunction. PDW had no significance with MACEs, yet NLR is found significant in predicting clinical LV failure and arrhythmias.