A year after detecting the first COVID-19 case in Nigeria, data on the trend and pattern of morbidity and mortality are still emerging. Therefore, this study identifies the outcome of patients with COVID-19 in an isolation and treatment facility in Nigeria. This was a retrospective analysis of medical records for 327 laboratory-confirmed cases of COVID-19 patients in Stella Obasanjo Hospital, Benin, Edo state, South-south Nigeria. Extracted data included age, sex, comorbidities, the severity of illness, duration of hospitalization. Data was analyzed using the IBM SPSS version 22 software. Values <0.05 were regarded as significant. The majority of the study population were males (63.2%), and the mean age was 44.5 years. 146 participants had at least one comorbidity, with hypertension (61.5%) and diabetes (17.1%) being the most common. The mortality rate was (12.5%), and a higher proportion of patients with comorbidities died compared to those with no comorbidity. The trend of the morbidity and mortality pattern of patients with COVID-19 within the isolation and treatment facility showed higher adverse outcomes among those who presented with comorbid illnesses. Therefore, public enlightenment, vaccination, early detection, and targeted care for COVID-19 cases, especially those with comorbidities, are recommended.