Background: Sinonasal symptoms were usually reported to appear initially, yielding the symptoms important for the early detection of coronavirus disease 2019 (COVID-19). This study was conducted retrospectively to investigate the detailed sinonasal manifestations and dynamic profile of real-time reverse transcription polymerase chain reaction (RT-PCR) results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in COVID-19 patients longitudinally. Methods: This retrospective study included 11 consecutive patients. The prevalence, timing and severity of sinonasal manifestations were analyzed. Oropharyngeal, nasal, sputum and stool specimens were collected to detect RT-PCR for SARS-CoV-2 over COVID-19 period. Results: Among the 11 patients, 6 (54.5%) were female, and the median age was 51 (IQR, 36-62) years. Seven patients (63.6%) experienced sinonasal symptoms, with 6 (54.5%) exhibiting sinonasal symptoms on the onset day. Seven patients (63.6%) demonstrated nasal obstruction, 5 (45.5%) had rhinorrhea, and 4 (36.4%) exhibited olfactory dysfunction. All six patients with sinonasal symptoms on the onset day had non-severe infections. Most patients (85.7%) with sinonasal symptoms had non-severe infections. Sinonasal symptoms commonly appeared early. The positive RT-PCR rate for SARS-CoV-2 in various specimens was highest in the first week (73.3%), then gradually decreased over the disease course, but 3 patients (27.3%) had experienced a long-lasting fluctuated positive RT-PCR results since 29 days of illness in both groups, especially for two patients with airway comorbidities. Conclusions: Sinonasal symptoms were more prevalent in patients with mild or moderate COVID-19 and usually appeared early. In addition, regular nucleic acid testing for SARS-CoV-2 should be considered for COVID-19 patients with certain airway comorbidities.