Background: The Covid-19 pandemic affected primary health care in various ways and general practitioners (GPs) take a key position in caring for patients with persistent Covid-19-related symptoms, also referred to as Long Covid. In this study, GPs’ knowledge, experiences and opinions on Long Covid, as well as the definition being used by GPs is investigated to provide more insight in the care for Long Covid patients in primary care. Methods: An online questionnaire, validated by experts, was distributed to all Belgian GPs through established national GP networks (SGP network, Domus Medica and SSMG) during spring 2022. The survey has 16 (ordinal, open-ended or multiple choice) questions on Long Covid. To characterize GPs, practice and demographic characteristics were collected. A case definition for Long Covid was not included, as there was no widely accepted definition available in general practice at the timing of the study. Descriptive and analytic statistics were performed. Results: A total of 105 GPs responded to the survey. GPs were well distributed across all Belgian regions and practice type. Female GPs represented 58.1% and mean age was 51 years (IQR: 38-63). Most of GPs reported that they did not have sufficient scientific knowledge on Long Covid, they reported lack of availability of reliable information on Long Covid diagnosis and treatment, and felt that accessibility to educational material on Long Covid was limited. For the diagnoses of Long Covid, 60.0% reported that a positive Covid-19 test result is a minimum requirement when speaking about Long Covid complaints. The commonest criteria utilized by GPs for diagnosing Long Covid was the duration of symptoms (from 4 weeks to 5 months) and on the basis of diagnostic criteria by the GP. 58.1% of GPs stated that Long Covid should be considered a chronic disease. The majority (75.2%) of participating GPs reported to have cared for Long Covid patients (independently of practice type, GP’s gender or age). These patients suffered mainly from fatigue ...