We assessed whether the previously observed relationship between socioeconomic status (SES) and short-term mortality (pre-hospital mortality and 28-day case-fatality) after a first acute myocardial infarction (AMI) in persons <75 years, are also observed in the elderly (i.e. ≥75 years), and whether these relationships vary by sex. A nationwide register based cohort study was conducted. Between January 1st 1998 and December 31st 2007, 76,351 first AMI patients were identified, of whom 60,498 (79.2 %) were hospitalized. Logistic regression analyses were performed to measure SES differences in pre-hospital mortality after a first AMI and 28-day case-fatality after a first AMI hospitalization. All analyses were stratified by sex and age group (<55, 55-64, 65-74, 75-84, ≥85), and adjusted for age, ethnic origin, marital status, and degree of urbanization. There was an inverse relation between SES and pre-hospital mortality in both sexes. There was also an inverse relation between SES and 28-day case-fatality after hospitalization, but only in men. Compared to elderly men with the highest SES, elderly men with the lowest SES had a higher pre-hospital mortality in both 75-84 year-olds (OR = 1.26; 95 % CI 1.09-1.47) and ≥85 year-olds (OR = 1.26; 1.00-1.58), and a higher 28-day case-fatality in both 75-84 year-olds (OR = 1.26; 1.06-1.50) and ≥85 year-olds (OR = 1.36; 0.99-1.85). Compared to elderly women with the highest SES, elderly women with the lowest SES had a higher pre-hospital mortality in ≥85 year-olds (OR = 1.20; 0.99-1.46). To conclude, in men there are SES inequalities in both pre-hospital mortality and case-fatality after a first AMI, in women these SES inequalities are only shown in pre-hospital mortality. The inequalities persist in the elderly (≥75 years of age). Clinicians and policymakers need to be more vigilant on the population with a low SES background, including the elderly.