Population growth in Grand Lomé is increasing households’ dependence on food markets in a context of rising prices. This study analyzes the price instability of staple foods, its determinants, and its effects on the coping strategies of urban households. It is based on a mixed-methods approach combining quantitative surveys of 245 traders, 210 buyers, and 310 households, as well as interviews with institutional stakeholders. The results reveal price increases of up to 79% and non-stationarity in the price series for maize, local rice, cowpea, gari, fish, and oil, while those for yam and tomato remain stable. Logit modeling identifies constraints related to insufficient access to storage as the most significant factor, followed by transport costs, taxation, access to credit, access to information, and product quality. Faced with this instability, more than 35% of urban households spend a major portion of their income on food and increasingly rely on street food, raising nutritional and health concerns. The findings advocate for urban policies that combine reduced logistical and fiscal costs, improved access to credit and market information, and risk financing mechanisms to sustainably strengthen urban food security, particularly in Grand Lomé, Togo.