The problem of indiscriminate waste disposal dates back to the earliest urban settlements in human society. The trend has been on the increase across many societies including Nigeria. This paper examined the nature and effect of waste generated in Nasarawa State, Nigeria. The study adopted the Reasoned Action Theory to explain the nature of waste generated in the study area. A cross-sectional survey design was adopted for the study. A sample of400 respondents was drawn through simple random, systematic sampling, clustered and purposive sampling techniques in the selection of Local Government Areas, electoral wards, towns/villages, main streets, houses, households and individuals. Primary data were generated through the use of questionnaire and in-depth interview. The questionnaire copies were analysed quantitatively using simple percentage while test frequency tables, mean and in-depth interview were unbundled using content analysis. The findings revealed that decomposed food items, empty sachet water packs and water bottles, empty engine oil gallons, used and unused drinking straw, sachets of all kinds, biscuit, condemned zincs and building materials were the solid wastes indiscriminately disposed in the study area. The study recommends that the Nasarawa State Waste Management Board should intensify the collection of solid wastes from the doorsteps of residents for appropriate recycling to mitigate the associated health and environmental hazards associated with the indiscriminate disposal of solid waste in the study area.