It is found naturally in carobs (Ceratonia siliqua), in vanilla, and in the root of Arnica dulcis, and as an ethyl ester in croton oil.

[7] It can also be prepared by the high pressure hydrocarboxylation (Koch reaction) from propylene:[7] Isobutyric acid can also be manufactured commercially using engineered bacteria with a sugar feedstock.

[8] Many routes are known including the hydrolysis of isobutyronitrile with alkalis and the oxidation of isobutanol with potassium dichromate in the presence of sulfuric acid.

[6] Isobutyric acid and its volatile esters are present naturally in a wide variety of foods and, at varying concentrations, can impart a range of flavors.

[12] In humans, isobutyric acid is a minor product of the gut microbiome and can also be produced by metabolism of its esters found in food.