The research study examined manufacturers’ negligence and its effects on consumer behaviour (cb) in South West Nigeria. The objectives of this study is to create a platform to explore the recklessness of manufacturers which is due to their negligence and its effects on cb with reference to South West Nigeria, to establish the effects of total quality management on manufacturers’ negligence, to determine the effects of consumption of sub-standard products on cb, to evaluate the impact of manufacturers’ marketing activities, to determine the effects of defective products on consumer exit, to show the effects of consumer service on cb, and to determine the effects of manufacturers’ negligence on cb. The study used survey research method with structured questionnaire and four hypotheses. Regression statistics was used to test the hypotheses and the result and findings show that f= 51.62, df= 1, and p value <0.05, thus manufacturers’ negligence has significant effect on cb
