To determine whether the decrease in creatinine clearance is a risk factor associated with mortality in patients with Acute Coronary Syndrome. Material and Methods: A retrospective, cross – sectional, case – control study was conducted at Regional Hospital of Trujillo. The sample (n = 192) was divided into 2 groups: Group I (cases: patients with Acute Coronary Syndrome who died within 30 days after diagnosis) and Group II (control: patients with Acute Coronary Syndrome who did not die in the first 30 days after diagnosis) at a ratio of 48 and 144 patients respectively. Results: The patient stratification by sex and mortality reports a rate of 20 % of deaths in men and 32.5% in women; by age group and mortality has a rate of 5.3% in < 50 years; 16.9 % in 50 – 65 years, and 32.5% in those > 65 years. The percentage decrease in creatinine clearance in patients who died within 30 days ...