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Background Secretory type-II phospholipase A2 (sPLA2-II) is a cardiovascular risk marker since higher levels of this acute phase protein imply an increased risk for coronary artery disease. Moreover, it is hypothesized that local activity of sPLA2-II in the atherosclerotic plaque facilitates an inflammatory response to induce plaque instability or rupture. We have studied the presence of sPLA2-II in culprit lesions in the coronary arteries of patients with acute myocardial infarction (AMI) or angina pectoris. Materials and methods We performed a histological examination of culprit lesions in 41 patients with stable (SAP) or unstable angina pectoris (UAP), or AMI using directed coronary atherectomy (DCA). Frozen slides were analysed immuno-histochemically for the presence of sPLA2-II, macrophages and smooth muscle cells. Immunopositive areas were calculated as a percentage of the total tissue area using image analysis software. Results Intracellular sPLA2-II was found in atherosclerotic lesions in the macrophages of the intima as well as in vascular smooth muscle cells. Next to this, extracellular sPLA2-II depositions were also found. These depositions were significantly more extensive in patients with AMI, i.e. 26%median[6%25th(percentile)–44%75th(percentile)] of the intima area, than in patients with SAP 0%median (0%25th–10%75th; P = 0·013) or UAP 0%median (0%25th–0%75th; P = 0·04). Conclusions Extracellular sPLA2-II is more abundantly present in atherosclerotic culprit lesions that have led to myocardial infarction. This suggests a role for extracellular sPLA2-II in the development of complications of atherosclerotic lesions in coronary arteries. [ABSTRACT FROM AUTHOR]