OBJECTIVES: We investigated, wheter environmental temperature and workdays, beyond the well known risk factors, might have an impact on the figures of heart attack cases in Hungary. METHODS: Data analysis and retrospective data collection was used among patients diagnosed with heart attack at the Cardiology Department of the University of Pecs, Hungary in the time period between January 1, 2000 and December 31, 2004. Weather data were obtained from the Local Service of the National Weather Institute, Pecs, Pogany Airport Base. In the time period under investigation, 81.956 patients were admitted with the above diagnosis. Analysis of variance and linear regression analysis were used as statistical methods. RESULTS: We found that the environmental temperature influenced the incidence of heart attack in 0.79 %. This result was found to be significant (p <0.01). Above 0 Co there were more heart attack cases diagnosed than below it. We observed a steady decrease in the incidence from Monday to weekend. During weekend days markedly less cases were recorded comparing to weekdays (p: 0.110 MT[0.108;0.112] vs. p: 0.155 MT[0.153;0.158], respectively). Furthermore, there was a peak in the number of cases on Monday and a drop during the weekend. CONCLUSIONS: Environmental temperature has an effect on the change in figures of heart attack cases, thus, we believe, it plays an important rople in the disease.