The contamination of indoor air is largely from the gases consumption for manufacture and combustion processing. A comprehensive analysis of indoor air pollution by nitrogen oxides shows that the extent of indoor air pollution and consequent exposure varies as a result of many factors mainly the gas consumption, burning intensity, differing distribution of appliances and their level of use. This study aims to formulate a mathematical model for the production of nitrogen oxides indoors. The physical processes that determine the concentrations of indoor nitrogen oxides as a function of outdoor concentrations, indoor emission rates and related characteristics have been mathematically described. The developed mathematical model has been parameterized for working environment. The modeling of the indoor nitrogen oxides occurrence and model verification is presented in the paper