BackgroundWe described the demographic/clinical characteristics and in-hospital outcome of patients with COVID-19 at the University of Nigeria Teaching Hospital (UNTH) during the first wave to inform evidence-based responses during subsequent waves in Africa. MethodologyWe conducted retrospective cohort analyses of adult patients ≥18 years with PCR or GeneXpert-confirmed SARS-CoV-2 infection. Data was extracted from patients’ medical records from 1st May to 30th September 2020. Based on disease severity, patients were either hospitalized (82) or managed at home (90). Logistic regression and cox-proportional hazard models were used to determine predictors of severe COVID-19 disease and in-hospital mortality, respectively. ResultsOf 172 cases, 113 (65.7%) were males, and the mean age was 45 ± 19 years. The majority were urban dwellers (72.1%), 19.8% had a positive history of contact with a confirmed/suspected case, 15.7% were healthcare workers while 68 (39.5%) had co-morbidities. Symptomatic patients comprised 73.3% of cases. Fever (p=0.02) and breathlessness (p=0.03) were commoner in males while diarrhoea (p<0.01) was predominant in females. On multivariate analysis, severe COVID-19 was predicted by the presence of co-morbidity (AOR= 14.44, 95% C.I= 4.79- 43.58, p <0.001)and prior antibiotic/antimalarial use (AOR= 6.35, 95% C.I= 2.24- 18.05, p =0.001) while being a non-healthcare worker (AOR= 0.18, 95% C.I= 0.04-0.78, p=0.02) was protective. However, none of the variables assessed predicted in-hospital mortality.Conclusion Our findings underscore the contributions of demographic variables in COVID-19 transmission and gender differences in clinical presentation. Underlying comorbidity likewise prior antimicrobial use increased the likelihood of severe COVID-19. The absence of mortality predictors in our study may be related to the relatively small number of deaths. Further studies are recommended to unravel the predominance of severe disease in healthcare workers.