It is known that air pollution and meteorological parameters have a negative effect on various respiratory and cardiovascular parameters. In this study, the relationship between emergency hospital admissions for acute coronary syndrome (ACS) and the meteorological and air pollution parameters over the same period were investigated. Some 2889 patients admitted to the emergency internal medicine unit between 1997-2001 were included in this study. The number of patient admissions per month with a diagnosis of ACS were determined and the relationship between meteorological parameters (pressure, temperature, humidity) and mean values of parameters of pollution including carbon monoxide (CO), sulphur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2), mass of particles smaller than 10 mu m (PM10) were investigated. Monthly admission figures for ACS were positively correlated with pressure and negatively correlated with temperature. No relationship between air humidity and admission for ACS was detected. There was also positive correlation between ACS and SO2, CO, NO and PM,, levels. The results showed that the most important meteorological parameter that increased the number of admissions for ACS was a decrease in air temperature, and the most important pollution parameter was SO2. Admission for ACS significantly increased in winters and springs in comparison with summers (RR = 1.15 %95 CI(1.039-1.279); RR = 1.16 %95 CI(1.046-1.291)). Air pollution and meteorological parameters should be seen as a widespread public health problem, which can trigger admission and even death due to ACS. Greater effort should be expended to further lower air pollution levels.