Aim: We evaluated the COVID-19 threat in patients receiving intravesical BCG therapy which has immunotherapeutic effects and is of vital importance in most of the individuals with high-risk non-muscle-invasive bladder cancer (NMIBC) and investigated the need for postponement of this therapy. Methods: A total of 71 patients, who were diagnosed with high-risk NMIBC and on intravesical BCG treatment regularly (induction or maintenance), were enrolled in the study. The patients were classified into two groups depending on whether they were diagnosed with COVID-19 during the pandemic period or not. Results: Of 71 patients, 26 underwent a COVID-19 polymerase chain reaction test with clinical suspicion during the pandemic period. Of these 26 patients, 4 were diagnosed with COVID-19. Age of the patients, working status (working/retired), compliance with containment measures against the pandemic, number of BCG courses, adverse effects after BCG therapy, and systemic immune-inflammation index, which is an inflammation-related parameter, were not different between groups (p>0.05). Neutrophil/lymphocyte ratio was significantly higher in the COVID-19 positive group (p<0.05). COVID-19 positivity was higher in age groups 50-64 (6.6%) and 65-80 (5.8%) years than that in similar age groups of the normal population. Conclusion: Every effort should be made to administer intravesical BCG treatment in high-risk NMIBC patients even during the pandemic period. However, increased risk of COVID-19 transmission should be kept in mind and protective measures against COVID-19 for healthcare providers and patients before the procedure should be taken optimally. The procedure should be postponed in patients with lymphopenia in recent complete blood count.