This study shows the mathematical modeling of 2019 novel coronavirus (2019 – nCoV) pandemic and reinfection in Nigeria using SEIAHQR model. We use both estimated and assumed parameters in our computations. The available statistical data regarding COVID-19 in Nigeria from its date of arrival till May 17, 2020 (22.00 WAT) was used to estimate some parameters, understand and predict the spread and reinfection of the virus. The disease free and endemic equilibrium was investigated using Jacobian transformation. The analysis carried out using the estimated parameters showed that the disease free-equilibrium point is stable. The basic reproduction number of the model was calculated and shown to be less than one. The numerical simulation shows that there is 94% chances of secondary reinfection when infected and asymptomatic individuals interact with the susceptible and exposed individuals through contact, hence the need for reinforced effort from the government, decision makers and stakeholders in compliance to all preventive measure as directed by World Health Organization (WHO) can effectively control the spread of this deadly virus in Nigeria.