Around the world, various vaccines have been developed to prevent the SARS-CoV-2 virus infection and consequently the COVID-19 disease. However, many patients continue to report persistent symptoms after the acute phase. Since gathering scientific information on long COVID and post-COVID syndrome has become an urgent issue, we decided to investigate them in relation to the vaccination status of patients from the STOP-COVID registry. In this retrospective study, we analyzed data from the medical visit after contraction of COVID-19 and follow-up visits in the 3rd and 12th month after the disease. In total, 801 patients were included in the analysis. The most frequent complaints after 12 months included deterioration of exercise tolerance (37.5%), fatigue (36.3%), and memory/concentration difficulties (36.3%). In total, 119 patients declared that they had been diagnosed with at least one new chronic disease since the end of isolation, and 10.6% required hospitalization. The analysis of individual symptoms revealed that headache (p = 0.001), arthralgia (p = 0.032), and dysregulation of hypertension (p = 0.030) were more common in unvaccinated patients. Considering headache and muscle pain, people vaccinated after the disease manifested these symptoms less frequently. Subsequent research is needed to consider vaccines as a preventive factor for post-COVID syndrome.