Background and Aims: This study aims to investigate the associations of blood groups on Long-Term COVID patients who applied to the COVID-19 Follow-up Center. New comorbidities after COVID-19 were also evaluated. Methods: This study was designed retrospectively with patients who were admitted COVID-19 Follow-up Centre between 13th December 2020 and 01st November 2021. The study sample consisted of 502 patients divided into four groups according to their blood types. Patients were analyzed according to their symptoms and our findings after COVID-19 by blood group variable. Newly diagnosed co-morbidities were asked to our patients and the drug history of the patients was investigated Results: A total of 502 COVID-19 patients were retrospectively analyzed and the mean age was 55.5(±13.2) years. Patients were predominantly female (263/502) [52.4%]. While long-term COVID-19 symptoms were observed in 76.9% of the patients, extreme fatigue (46.2%) and ongoing shortness of breath (32.9%) were observed most frequently. When the long-term COVID symptoms were evaluated, heart palpitation was the only symptom related to blood groups A and B compared to AB and O (p=0.048). No significant relationship was found between the blood groups of the patients and the symptoms and course of the disease. In addition, there was no significant difference in the ongoing symptoms and inflammatory parameters like C-Reactive Protein and Lymphocyte. Conclusion: This study demonstrated that there was no difference between blood types and long-term COVID-19 patients' clinical features.