Microparticles circulate in plasma and have recently emerged as potential inflammatory markers in cardiovascular disease. They are fragments of cell membranes that express CD antigens and are present at elevated levels in patients with acute coronary syndrome. We have developed a novel method for the rapid detection of microparticles in plasma using a fluorescence-based antibody array system. Isolated microparticles are captured on anti-CD antibody spots immobilized on a nitrocellulose membrane. These CD antibodies are directed against extracellular epitopes while the intracellular exposed surface of the microparticles are labelled with a fluorescent anti-annexin antibody. The array is then scanned and quantified. A pilot study was undertaken to compare microparticle CD antigen expression in acute coronary syndrome and healthy subjects. Ten CD antigens (44, 45, 54, 62E, 79, 102, 117, 130, 138, 154) had significantly increased expression in the disease group relative to the healthy controls. These results were then verified using flow cytometry and scanning electron microscopy. Even though we have focused our analysis on changes in microparticle CD antigen expression, this technique is amenable to analysing other surface markers. Microparticles can be derived from a wide variety of cell types and so selection of the primary antibody can be tailored to the cell origin that is to be investigated.