Patients face being deregistered from a GP practice if more "derogatory comments" about the service and staff are posted online, doctors have warned.
Park House Surgery in Prestatyn said it was operating a zero-tolerance policy to online abuse.
Bosses warned comments could be "viewed as a potential breakdown in the doctor-patient relationship, and may result in you being removed from our list".
They said feedback was welcomed, but not "derogatory or hurtful comments".
In a statement published on its website, the surgery said if further comments were made, it "may contact the patients involved and invite them in to have a face to face discussion about the issues that they have".
The statement continued: "We welcome all feedback, as it gives us the opportunity to review the services that we provide and where necessary or appropriate, make any changes or improvements.
"However, we would ask that rather than posting derogatory or hurtful comments about the practice or any of our staff on social media, or if there are any aspects of the service that you are not entirely happy with, please speak to us about this or put your comments to us in writing giving us the opportunity to respond."
Senior partner Dr Nitin Shori told BBC Wales the social media policy was in line with other practices in the UK which had "removed patients from their lists as a result of social media abuse".
"As a practice, we welcome all feedback but would encourage patients to follow correct procedures so that matters can be reviewed and handled appropriately.
"We have a duty to protect NHS staff from abuse in line with the longstanding NHS zero-tolerance policy."