Biologically active oxidized phospholipids can initiate and modulate many of the cellular events attributed to inflammation leading to atherosclerosis. Produced by enzymatic or non-enzymatic processes, these molecules interact with various cells via specific receptors and in general give rise to inflammatory signals. There is considerable evidence that oxidized phospholipids accumulate in vivo and play significant roles in atherosclerosis and thrombosis, suggesting that oxidized phospholipids could be biomarkers that reflect the global extent of these diseases in vivo. Thus, understanding the biosynthetic pathways, receptor specificity and signaling processes of oxidized phospholipids is important in understanding atherosclerosis, thrombosis and related inflammatory diseases.