© 2021 John Wiley & Sons LtdAims: The impact of ongoing PCR positivity on COVID-19 patients and the strategy and period of isolation were not fully understood. We aimed to investigate the factors that cause prolonged PCR positivity and its clinical impact on COVID-19 infection. In addition, we searched for an answer on what length of time would be best for isolation. Methods: Patients with confirmed COVID-19 infection were included in this retrospective study. Patients with PCR positivity (after symptom onset) longer than 14 days and PCR positivity less than 14 days were compared. The relationship between duration of symptoms and PCR negation time was examined. Results: A total of 339 patients were included in this study. Fifty (14%) patients had prolonged PCR positivity after 14 days. Demographic and clinical features, and clinical outcomes (disease severity and mortality) were similar among the two groups. Age (p 0.035) and symptom duration at admission (P <.001) were found as independent factors for prolonged PCR positivity. Median of total symptom duration was 7 days (IQR: 5-11). The duration of negative conversion of PCR test was median 9 days (IQR: 7-12) after symptom onset and PCR tests became negative 3 days (IQR: 2-5) after symptom improvement. Conclusions: We found that ongoing PCR positivity has no detrimental effect on the course of the disease and clinical outcomes in COVID-19 patients. In addition, our results showed that isolation may be discontinued 10-14 days after symptom onset and/or after 2-5 days after resolution of symptoms. This results also support WHO and ECDC recommendations on this matter.