The fatty acid oxidation takes place in mitochondria. Fatty acids are oxidised by most of the tissues in the body. However, brain, erythrocytes, and adrenal medulla cannot utilise fatty acids for energy requirement.

The β-oxidation of fatty acids involves the following three stages:

1. Activation of fatty acid occurs in the cytosol
2. Transport of fatty acids into mitochondria
3. Beta oxidation in the mitochondrial matrix