A descriptive study was carried out in the Emergency Department of Punjab Institute of Cardiology, Lahore, from Oct 2022-April 2023 to assess the incidence of 30 days mortality in STEMI patients with varying hematocrit levels. A total of 440 cases with ST-segment elevation MI with varying hematocrit levels (anemia and erythrocytosis) were included in the study. In our study, the average age was 44.12+10.16 years, 273 (62%) were male, and 167 (37.9%) were females; frequency of different hematocrit levels was recorded, which showed that 263 (59.7%) had anemia and 177 (40.2%) had erythrocytosis. Out of 263 cases of anemia, 26 (9.8%) and out of 177 cases of erythrocytosis, 11 (6.2%) were recorded with mortality, while the remaining 237 (90.8%) cases of anemia and 166 (94.3%) of erythrocytosis had no mortality, the p-value was calculated as 0.17 which shows the insignificant difference between the two groups. We concluded that the frequency of 30 days mortality in STEMI patients is higher in anemic patients than in erythrocytosis, but hematocrit levels could be used as a biomarker for mortality in STEMI.