A potentially life-saving defibrillator was removed from its housing and dumped under a bag in Broad Street on Monday morning.
The incident, which is believed to have happened around 11am, was witnessed by a member of the public who took the unit to Wokingham Town Council.
It appears the offender may have intended to return to collect the unit later.
Katy Hughes, town clerk at Wokingham Town Council, told Wokingham Today: “I’d like to express my sincere thanks to the member of the public for acting quickly and bringing the defibrillator to us for safe keeping.”
The council has placed a sign at the location outside the former post office, directing people to the nearest alternative town centre defibrillator which is adjacent to Waitrose.
South Central Ambulance confirmed it was aware of the incident.
A spokesperson said: “The Defib itself is safe and in working order, and that the access code will be changed before it is reinstated.”
The equipment was donated in 2015 by The Wokingham Community First Responders, who provided a vandal proof casing and offered 10-year maintenance.
The defibrillator is aimed to be simple to use and available to any member of the public who attends a medical emergency involving potentially life threatening cardiac conditions.
Wokingham Town Council took on ownership of the phone box after BT decided it was of low use.