Municipal solid waste open dump site operation is an important element of waste management in Nigeria, both today and in the future. Dump site fires are common occurrences in the study area. The contribution of municipal solid waste dump site fires to atmospheric pollution in the Niger Delta, Nigeria has been assessed experimentally. Five (5) municipal solid waste dump sites where fire incidence is a frequent and regular occurrence were chosen for the study. At each of the identified municipal solid waste dump site, eight (8) air quality monitoring parameters, suspended particulate matter (SPM₁₀), nitrogen dioxide (NO₂), carbon dioxide (CO₂), carbon monoxide (CO), sulphur dioxide (SO₂), methane (CH₄), ammonia (NH₃) and Hydrogen sulphide (H₂S) were determined using a series of hand held air quality monitoring equipment. Results indicate the levels of SPM ranged between 773 and 801 μg/m³ and the levels of CO ranged between 133.7 and 141.6 ppm. The levels of CO₂ ranged between 401 ppm and 404.5 ppm while that of NO₂ ranged between 21.0 ppm and 27.3 ppm. The levels of SO₂ ranged between 27.7 ppm and 37.1 ppm while that of NH₃ ranged from 14.7 to 19.5 ppm. The levels of methane in the study area ranged between 2310 ppm and 2771 ppm and within the vicinity of dump site fires H₂S concentration ranges from 3.4 to 7.7 ppm. Levels of SPM, CO, CO₂, and CH₄ within the vicinity of the dump site fires were above regulatory limits. Dump site fires in the study area could threaten the health of anyone especially the dump site workers that are regularly exposed to the thick smoke and can be implicated in climate change debate. There is a need to develop better practices with regard to municipal solid waste open dump site operation and emission control.