North Yorkshire Police said there have been seven burglaries at the Magnesia Well Tea Room since March 2017, with repair costs totalling around £6,000.
The latest burglary happened between 10pm and 10.40pm on October 18 and involved two young men, believed to be teenagers.
Police, who released information on the incident for the first time last week, said raiders smashed their way into the cafe and stole low-value items of food.
Police are now appealing for anyone who may have seen anything around the times of the burglary to get in touch.
The spate of incidents in the Valley Gardens, at Magnesia Well cafe in particular, has also prompted concern by the local authorities and residents groups.
In August Harrogate Borough Council condemned “mindless vandalism” after damage to the cafe and roof tiles at a hut in Valley Gardens which is popular with families and children.
It said it would be deploying its warden patrols and CCTV cameras in an attempt to track down the culprits.
Coun Andy Paraskos, the council’s cabinet member with responsibility for parks, said: “This is mindless vandalism by a group of people intent on ruining things for other people.
“We work hard to provide facilities like these and it’s upsetting when they are damaged in this way.”
The school holidays are traditionally a bad time for attacks on the cafe in the Valley Gardens but this year’s tally of attacks has been worse than normal.
A North Yorkshire Police statement read: “It happened at Magnesia Well Tea Room, Valley Gardens, between 10pm and 10.40pm on 18 October 2018 and involved two males believed to be aged in their teens.
“In particular, we are appealing for information about the identity of the two males involved in the commission of this offence.
“The tea room has been targeted seven times since March 2017, costing around £6,000 in repair costs. The offenders have smashed their way into the property and once inside have only stolen low-value items of food.
“Anyone with information that could assist the investigation should contact North Yorkshire Police on 101, select option 1 and quote the North Yorkshire Police reference number 12180195353.”