The escalating use of tobacco and alcohol has become a pressing concern for policymakers worldwide due to its severe impact on public health. However, there is a paucity of research focusing on the determinants of tobacco and alcohol spending, particularly in Tanzania. The aim of this study was to examine the factors influencing tobacco and alcohol expenditures with their implications on food poverty and healthcare costs in Tanzania. The analysis relied on secondary data obtained from the 2017/2018 Household Budget Survey, while Tobit, logit and generalised linear models were employed for data analysis. Being male, unmarried and residing in rural areas exhibited positive associations while age had an inverted U-shaped relationship with tobacco and alcohol expenditures. Increased spending on these substances amplified the incidence of food poverty by 0.0002%, particularly among married couples. Tobacco and alcohol expenditures were found to jointly contribute to a 0.01% rise in healthcare costs. Results underscore the importance of targeting interventions towards mitigating the adverse effects of tobacco and alcohol consumption, with a particular focus on youth, rural areas, males and unmarried household heads. Such interventions have the potential to alleviate the incidence of food poverty and reduce the financial burden on healthcare systems.