It is expected that GPs are increasingly confronted with a large group of patients with symptoms persisting three weeks after initial symptoms of a mild (managed in the outpatient setting) COVID-19 infection. Currently, research on these persistent symptoms mainly focuses on patients with severe infections (managed in an inpatient setting) whereas patients with mild disease are rarely studied. The main objective of this systematic review was to create an overview of the nature and frequency of persistent symptoms experienced by patients after mild COVID-19 infection. Systematic literature searches were performed in Pubmed, Embase and PsychINFO on 2 February 2021. Quantitative studies, qualitative studies, clinical lessons and case reports were considered eligible designs. In total, nine articles were included in this literature review. The frequency of persistent symptoms in patients after mild COVID-19 infection ranged between 10% and 35%. Symptoms persisting after a mild COVID-19 infection can be distinguished into physical, mental and social symptoms. Fatigue was the most frequently described persistent symptom. Other frequently occurring persistent symptoms were dyspnoea, cough, chest pain, headache, decreased mental and cognitive status and olfactory dysfunction. In addition, it was found that persisting symptoms after a mild COVID-19 infection can have major consequences for work and daily functioning. There is already some evidence that symptoms of mild COVID-19 persist after 3 weeks in a third of patients. However, there is a lack of data about symptoms persisting after 3 months (long-COVID). More research is needed to help GPs in managing long-COVID. © The Author(s) 2021. Published by Oxford University Press.