Background and Objectives: The term long COVID refers to patients with a history of confirmed COVID-19 infection, who present symptoms that last for at least 2 months and cannot be explained by another diagnosis. Objectives: The present study aims to determine the most common symptoms of the long COVID syndrome and their impact on the quality of life. Materials and Methods: A prospective observational study was conducted on patients diagnosed with mild and moderate COVID-19 (based on a positive SARS-CoV-2 molecular diagnostic or rapid antigen test and severity form definition) at the Clinical Hospital of Infectious Diseases, Cluj-Napoca, Romania. Clinical examinations with detailed questions about symptoms were performed at the time of the diagnosis of COVID-19 and the six-month follow-up. Two years after COVID-19 infection, patients were invited to complete an online quality-of-life questionnaire regarding long COVID symptoms. Results: A total of 103 patients (35.92% males) with a mean age of 41.56 ± 11.77 were included in this study. Of the total number of patients, 65.04% presented mild forms of COVID-19. Data regarding the vaccination status showed that 83.5% were vaccinated against SARS-CoV-2. The most common symptoms at diagnosis were cough (80.6%), fatigue (80.4%), odynophagia (76.7%), and headaches (67.6%), with female patients being statistically more likely to experience it (p = 0.014). Patients with moderate forms of the disease had higher levels of both systolic (p = 0.008) and diastolic (p = 0.037) blood pressure at diagnosis, but no statistical difference was observed in the 6-month follow-up. The most common symptoms at 2 years (in 29 respondent subjects) were represented by asthenia (51.7%), headache (34.5%), memory disorders (27.6%), abdominal meteorism (27.6%), and arthralgia (27.6%). In terms of cardiovascular symptoms, fluctuating blood pressure values (20.7%), palpitations (17.2%), and increased heart rate values (17.2%) were recorded. Conclusions: If at the time of diagnosis, the most frequent manifestations of the disease were respiratory, together with headache and fatigue, at re-evaluation, asthenia, decreased effort tolerance, and neuropsychiatric symptoms prevailed. Regarding the cardiovascular changes as part of the long COVID clinical picture, some patients developed prehypertension, palpitations, and tachycardia.