AIMS: To investigate the risk of a first time myocardial infarction (MI) among different occupational categories in 25-64 year old men in Kaunas, Lithuania, a country in a transition market economy. METHODS: Case-control study among men aged 25-64 who were residents in Kaunas between 1997 and 2000. First time, non-fatal MI cases (n = 448) were identified from the MI hospital register (International Classification of Diseases, 10th revision, code I21). Controls (n = 1777) were selected and matched on age, gender, and city district of residence. Information was obtained on occupation, smoking, hypertension, psychosocial, and behavioural factors. The International Standard Classification of Occupations (ISCO) was used to code for occupational categories. The relation between MI and occupational categories was evaluated by logistic regression analysis, adjusting for a number of selected risk factors. RESULTS: Legislators, senior officials, and managers (1st ISCO category) had a twofold increased risk for MI compared to craft and related trades workers (7th ISCO category) after adjustment for age, district, smoking, hypertension, obesity, stress, education, and employment duration. An increased risk for professionals (2nd ISCO category) and plant and machine operators and assemblers (8th ISCO category) was also observed. Employment duration in the last occupation for 20 years and more almost doubled the risk of MI in the whole population. We also found an increased risk for other traditional IHD risk factors such as smoking and arterial hypertension. CONCLUSIONS: Differences in first time MI risk among occupational categories were found. Legislators, senior officials, and managers (1st ISCO category), professionals (2nd ISCO category), and plant and machine operators and assemblers (8th ISCO category) were at an increased risk. Differences in psychosocial factors in transition market economy countries may contribute to observed results.