Postprandial lipemia (PPL) refers to a dynamic sequence of plasma lipid/lipoprotein changes induced by ingestion of food. PPL results from absorption of digested dietary lipids which form chylomicrons (CM) and increased hepatic production of VLDL, stimulated by increased delivery of fats to the liver. In general, PPL occurs over 4-6 h in normal individuals, depending on the amount and type of fats consumed. The complexity of PPL changes is compounded by ingestion of food before the previous meal is fully processed. PPL testing is done to determine the impact of (a) exogenous factors such as the amount and type of food consumed, and (b) endogenous factors such as the metabolic/genetic status of the subjects, on PPL. To study PPL appropriately, different methods are used to suit the study goal. This paper provides an overview of the methodological aspects of PPL testing. It deals with markers of postprandial lipoproteins, testing conditions and protocols and interpretation of postprandial data. The influence of the meal itself will not be discussed as it is the subject of another paper in this series.