Soot is a mass of impure particles of carbon obtained from incomplete hydrocarbon combustion. Soot is an ultrafine air-borne pollutant and enters into the body through ingestion, skin contact and inhalation causing devastating effects on the blood cells. The aim of the study was to determine the effect of soot inhalation on methaemoglobin and oxyhaemoglobin levels of individuals resident in both Iwofe, Port Harcourt (exposed subjects) and Ihiala, Anambra state (control subjects). The study is a case control study involving residents of Iwofe, Rumuolumeni, who have been exposed to soot pollution in the environment for an average period of one year. Iwofe is in Port Harcourt, the capital of Rivers State, Nigeria. A total of fifty (50) test samples were obtained. Thirty control samples were obtained from subjects in Ihiala a city located in the South of Anambra state where illegal oil refineries and other major means of soot generation are not as comparable to what is present in Port Harcourt and its environs. Methaemoglobin and Oxyhaemoglobin concentrations were analyzed using spectrophotometric method. The data obtained was analyzed using SPSS for descriptive statistics (mean and standard deviations) and inferential statistics (t-test). The student t-test was used to test for difference in the methaemoglobin and oxyhaemoglobin levels between the exposed subjects and non-exposed controls and based on age groups and gender. An error of probability (p ≤ 0.05) is considered levels of exposed subjects showing the effect of soot inhalation. Activities of illegal oil refineries (a major source of soot pollution in the city) should be stopped along with other activities like burning of tyres, indiscriminate burning of wastes and gas flaring etc.