The man was assaulted by two men on Great Northern Road, close to its junction with Barron Street, at about 22:00 on Tuesday 19 May.
He suffered facial injuries and was taken to Aberdeen Royal Infirmary.
The two men involved were both described as being aged between 18 and 35 and about 5ft 10in tall.
The first man was described as being of average build, with short blond hair, and was wearing a white or light grey hooded top, light jeans and light trainers.
The second man was described as being slim.
Police have appealed for information after a 65-year-old cyclist was the victim of an "unprovoked and cowardly" attack in Aberdeen.