Aim: Although Turkey has one of the youngest populations when compared with those of European and Middle Eastern countries, the proportion of our elderly population has increased year-by-year and as has myocardial illnesses in parallel. The aim was to investigate the effects of the monthly, outdoor temperature and weekday variables on acute Myocardial Infarction (aMI) in the elderly, attending Emergency Departments (EDs). Methods: The records of patients aged 60 and over who had presented with aMI to three major EDs of a city in north-west Turkey between January 1998 and December 2000 were enrolled in the study. Patient records on the protocol register were reviewed retrospectively for date and month of presenting, age, gender, and outcome. Daily temperature records were taken from the Regional Weather and Meteorology Center. Student’s t test, Pearson Chi-square, ANOVA, and Logistic regression analyses were used for statistical analysis. Results: 79,123 elder patients had presented to the EDs during the study period. aMI was diagnosed in 1.56% (n=1,232) patients. The frequency of aMI in males was higher than that in females (p<0.001). aMI diagnosis in males was higher than that of females in April and November (p=0.027). There was a sudden 8.1 o C increase trend of the mean temperature in April and a 5.4 o C decrease in the mean temperature in November. Statistically significant independent predictors of fatal aMI were male gender (odds ratio [OR] 2.13, p=0.04), presentation to EDs in the September-October period(OR 3.43, p=0.01), and mean daily temperatures of between +1 o C and 15 o C (OR 3.21, p=0.008) and –22 and 0o C (OR 5.21, p=0.02). Conclusion: aMI and death from aMI were more frequent in the male gender (elder patients). The frequency of fatal aMI increased as the temperature decreased, especially when it fell below 15 o C. In addition to seasonal variability, a sudden increase or decrease in temperatures can be an important risk factor for aMI in the elderly. Independent predictors found in our study should be evaluated through further study.