Phosphatidylcholine (PC) is one of the major building blocks of biological membranes in mammalian cells. In PC, two fatty acyl chains are linked to the sn-1 and sn-2 positions of the glycerol backbone, and a head group containing a phosphate and choline is linked to the sn-3 position. The length and saturation of the fatty acyl chains of PC vary significantly and determine the biophysical and chemical properties of PC. In mammalian cells, active metabolism of PC takes place primarily through de novo synthesis, the remodelling cycle of deacylation and reacylation, and further modification of lysophosphatidylcholine. PC metabolism undergoes remarkable changes in obesity. In this mini review, we discuss PC metabolism and summarize recent advances about the important involvement of PC metabolism in obesity and obesity-related diseases.