The chapter provides a comprehensive overview of acyl lipid metabolism in Arabidopsis, detailing the pathways, enzymes, and genes involved in the biosynthesis and degradation of various types of acyl lipids. Acyl lipids serve multiple functions in plants, including membrane structure, energy storage, and protection from environmental stresses. The chapter is organized into sections based on the types of lipids produced and their subcellular localization, covering fatty acid synthesis and export, plastid glycerolipid synthesis, eukaryotic phospholipid synthesis, sphingolipid synthesis, mitochondrial lipid synthesis, triacylglycerol synthesis, lipid trafficking, cuticular waxes, cutin and suberin biosynthesis, and lipid degradation. It also includes methods for lipid analysis and a detailed summary of the lipid composition of Arabidopsis. The chapter highlights the complexity of these pathways and the importance of lipid metabolism in plant biology, with a focus on the latest advancements and unresolved questions in the field.The chapter provides a comprehensive overview of acyl lipid metabolism in Arabidopsis, detailing the pathways, enzymes, and genes involved in the biosynthesis and degradation of various types of acyl lipids. Acyl lipids serve multiple functions in plants, including membrane structure, energy storage, and protection from environmental stresses. The chapter is organized into sections based on the types of lipids produced and their subcellular localization, covering fatty acid synthesis and export, plastid glycerolipid synthesis, eukaryotic phospholipid synthesis, sphingolipid synthesis, mitochondrial lipid synthesis, triacylglycerol synthesis, lipid trafficking, cuticular waxes, cutin and suberin biosynthesis, and lipid degradation. It also includes methods for lipid analysis and a detailed summary of the lipid composition of Arabidopsis. The chapter highlights the complexity of these pathways and the importance of lipid metabolism in plant biology, with a focus on the latest advancements and unresolved questions in the field.