Police said dispatchers got a call around 8:25 p.m. from a man reporting that an armed man had just tried to rob him near the Webster/Cowper Parking Garage at 520 Webster St.
Officers arrived on the scene within two minutes but were unable to find the suspect.
Police said the victim, a man in his 50s, had taken a pause during a walk along a pathway on the south side of the parking garage when the suspect approached him on a bicycle.
The suspect pulled out a gun and demanded cash from the man.
The victim grabbed the suspect's arm and tried to wrestle his gun away, and the two men fell to the ground and struggled over the weapon, according to police.
The suspect kept a firm grip on the weapon, and the victim gave up and ran away.
No one was injured and no property was stolen.
Detective are actively investigating the incident and attempting to determine whether there is a possible link to three other armed robberies reported in Palo Alto in recent weeks.
Each of those robberies involved people walking in or near Downtown Palo Alto.
Police are reminding people to stay aware of their surroundings while out for walks and to report any suspicious activity immediately to 911.
Anyone with information about the attempted armed robbery Friday is asked to call police at (650) 329-2413. Anonymous tips can be emailed to paloaltotipnow.org or sent via text or voice message to (650) 383-8984.