The 73-year-old man was punched by a cyclist on the canal tow path near The Rosebank Beefeater while he was out walking with his daughter.
The incident took place at around 3.45pm on Saturday following an accidental collision between the man on the bike and his victim.
The perpetrator is descibed as aged 21 to 30, is of stocky build and was wearing dark clothing.
Police are still analysing CCTV footage in a bid to trace the suspect.
Inspector Ewan Wilson, of Falkirk Police Station, said: “This was an unprovoked and despicable assault on an elderly gentleman who was out walking with another member of his family.
“I would urge anyone with any information that could assist our inquiry to contact us.”
Members of the public who have any information connected to this crime are urged to contact 101.