Implementing litter prevention strategies is essential for cities of developing countries, especially due to the prevailing high incidence of littering and the urgent need to realize the adverse per capita environmental impact target of the sustainable development goals. In this article, we report the use of the prominent reasoned action approach ––in its original state and in an extended model with moral norms–– for exploring the key socio-cognitive determinants of individuals’ litter prevention intentions in Ghana. By analyzing the valid answers of 447 participants to a structured questionnaire on litter prevention, we found attitudes (β = 0.35, SE = 0.014, p < 0.001) and moral norms (β = 0.57, SE = 0.099, p < 0.001) as the most influencing determinants to individual intentions in the original and the extended models, respectively. The analysis suggests that individuals will stop littering their environments through the implementation of eco-friendly interventions aimed at eliciting self-responsibility and moral obligation. Campaigns targeted at demonstrating the effects of littering on drain blockage, flooding, and disease outbreaks may improve individual litter prevention attitudes. Installing waste receptacles in public spaces along with persuasive messages may also facilitate individual antilittering intentions. Apart from contributing to the implementation of a litter management strategy to reduce the flood risk and enhance the resilience of the Greater Accra region of Ghana, this research helps to close the literature gaps in litter prevention behavior, as well as support the modernization of the municipal solid waste management systems in developing countries.