ABSTRACT… Objectives:To determine the frequency of renal dysfunction in patients with acute coronary syndrome at a tertiary care hospital. Study design: Descriptive Cross-sectional study. Setting: Department of Cardiology, Nishtar Hospital Multan. Duration of study: Six months from November 2016 to May 2017. Subjects and Methods: Consecutive 285 patients who met inclusion criteria of our study were enrolled from department of Cardiology, Nishtar Hospital Multan. History was taken and relevant investigations were done. Computer based formula for MDRD eGFR was used to calculate eGFR in our patients. All these findings were entered in pre-designed, pre -tested study questionnaire. Data was entered and analyzed using computer based software SPSS version 20. All the quantitative variables of the study (such as age, serum creatinine level, GFR value) were calculated for mean and standard deviation. Frequencies and percentages were calculated for categorical variables like gender, residential area, socioeconomic status, level of education, H/O diabetes, H/O hypertension, H/O smoking and family history of IHD etc. Results: We studied 285 patients of acute coronary syndrome admitted in Cardiology department of Nishtar Hospital Multan, 210 (73.7%) were male and 75 (26.3%) female. One hundred eighty (63.2%) were from rural area and 105 (36.8%) were urban. One hundred thirty two (46.3%) were from low income group, 144 (50.5%) from middle income and 9 (3.2%) were from high income group. Two hundred four (71.6%) patients presented with chest pain and 72 (25.3%) presented with chest pain and shortness of breath. One hundred eight (37.9%) were hypertensive, 63 (32.6%) were diabetic, 135 (47.4%) were smokers and family history of IHD was present in 102 (35.8%) of the cases. eGFR was calculated by MDRD eGFR formula. eGFR was less than 30 ml/min/1.73 m 2 in 30 (10.5%) of the cases, 31-60 ml/ min/1.73 m 2 in 66 (23.2%) cases and eGFR was more than 60 ml/min/1.73 m 2 in 189 (66.3%) of the cases. Conclusion: The present study reveals that the substantial proportion of our study patients have underlying renal dysfunction. So eGFR estimation in ACS patients should be given due consideration. This will help in the management of these patients and may improve short and long term disease outcome. Further follow up studies especially in terms of morbidity and mortality in this sub-group of patients are suggested.