The paper investigates the residents’ level of usage on sources and vulnerability of urban residents to indoor pollution in Ogbomoso. It utilized multistage method of sampling to distribute a total of three hundred and seventy three (373) structured questionnaires to residents in the selected forty eight localities. Likert scale rating was employed to examine resident’s perception on the impacts of indoor air pollution. Resident Usage Index (RUI) and Residents Perceived Effect index (RPEI) with scale rating ranging from Not agreed (2), Partially Agreed (3), Agreed (4), Very much agreed (5) were developed to ascertain rating value placed by each resident. The average weight for each variable was computed. The findings reveals, highest index value of 2.30usage in perfume, germicides (2.61) insecticides (2.29) building materials (2.71) asbestos, lanterns (2.38), charcoal (2.20). The high perceived usage suggests most frequently used household materials that constitute indoor air pollution in the study area. The general effect from use of household materials varies from sneezing eye irritation, dizziness headache among others. Continuous usage and exposure to such household materials will undoubtedly cause major damage to organs of the vulnerable group if appropriate action are not put in place. The paper therefore, recommends use of local household material that are less free of pollutant and cleaner fuel should be made available by concerned Government. Also awareness programme to sensitize populace on associated danger of exposure to household materials that are prone to generate indoor pollution should be adopted.