4-Bromobenzaldehyde, or p-bromobenzaldehyde, is an organobromine compound with the formula BrC6H4CHO.

[3] It displays reactivity characteristic of benzaldehyde and an aryl bromide.

4-Bromobenzaldehyde may be prepared in the laboratory in two steps by oxidation 4-bromotoluene.

[4] In the first step, two bromine atoms are added to the methyl group of 4-bromotoluene by free radical bromination to form 4-bromobenzal bromide.

In the second step, the dibrominated methyl group is hydrolyzed with calcium carbonate, then steam distilled to collect 4-bromobenzaldehyde.