Background: Recurrences of herpes labialis (RHL) may be triggered by systemic factors, including stress, menses, and fever. Local stimuli, such as lip injury or sunlight exposure are also associated to RHL. Dental extraction has also been reported as triggering event. Case reports: Seven otherwise healthy patients are presented with severe and extensive RHL occurring about 2-3 days after dental extraction under local anaesthesia. Immunohistochemistry on smears and immunofluorescence on cell culture identified herpes simplex virus type I (HSV-I). Five patients reported more severe prodromal signs than usual. Although all the patients suffered from RHL, none had previously experienced RHL after dental care. Two patients required hospitalisation for intravenous acyclovir therapy, whereas the others were successfully treated with oral valaciclovir or acyclovir. Conclusion: Severe and extensive RHL can occur soon after dental extraction under local anaesthesia. Patients with a previous history of RHL seem to be at higher risk. It is not clear whether RHL is linked to the procedure itself, to the anaesthetic procedure or both. As the incidence is unknown, more studies are required to recommend prophylactic antiviral treatment in RHL patients who are undergoing extractions. Dentists should be aware of this potentially severe post-extraction complication.