Objective The aim of this study was to compare the number of deep vein thrombosis (DVT) cases during the quarantine period for COVID-19 to that of the last year. Methods This study was conducted as a single-center and retrospective study. All hospital admissions during April 2020 and May 2020 were screened from the hospital records, and DVT cases were recorded. Likewise, all hospital admissions during April 2019 and May 2019 were screened, and DVT cases were noted. DVT cases of both years were compared. Results Among 480931 patients admitted to our hospital in April 2019 and May 2019, DVT was detected in 82 patients (0.017%) (47 males, 35 females) with a mean age of 56.99 ± 9.1 years (ranges 39 to 79 years). Besides, among 145101 patients admitted to our hospital in April 2020 and May 2020, DVT was detected in 123 patients (0.084%) (51 males, 72 females) with a mean age of 58.64 ± 8.9 years (ranges 40 to 83 years). Despite the decrease in the total number of patients admitted to the hospital, there was a significant increase in the number of DVT patients. Interestingly, there were only two symptomatic pulmonary-embolism cases in the 2019 period, whereas there were seven symptomatic pulmonary embolisms secondary to DVT in the 2020 period. Unfortunately, one patient died due to pulmonary embolism secondary to DVT in 2020. The previous history of DVT was remarkable in patients admitted during the COVID-19 confinement. Conclusion In conclusion, COVID-19 confinement seems to be associated with increased rates of DVT. Strict preventive measures such as exercise training or prophylactic drug use should be considered to prevent immobility-related DVT during the COVID-19 quarantine.