Recent high food prices and changes in the world food situation are exacerbating the conditions of households that are vulnerable to food insecurity, especially those with weak livelihood strategies. To address the impact of these and other stressors it is necessary to develop a deeper understanding of concepts such as ‘vulnerability’ and ‘food insecurity’. This is challenging as both concepts are used rather loosely in the food security literature, despite both having at least two dimensions. Vulnerability has an external and internal dimension, and food insecurity has a temporal and intensity dimension. However, assessments are often only concerned with one dimension at a time. An exploration of the two concepts suggests that in both cases the dimensions need to be combined in order to understand the different interactions and the interconnections between different dimensions and the multiple levels of the systems in which they are embedded. This combination of dimensions is important for understanding the significant role that livelihoods play in the accumulation of assets and for accessing food. It makes the understanding of the multiple causes and consequences of vulnerability and food insecurity for different households clearer. Those households and individuals considered chronically poor or food-insecure are likely to experience severe food insecurity in the long-term, as a result of their weak livelihoods and minimal assets. Consequently, future studies on vulnerability to food insecurity should focus on these chronically food insecure households in order to determine the multidimensional nature of the stressors they experience and their ability to cope and adapt to these stressors. This would contribute to our understanding of the contexts in which the data from larger quantitative studies are embedded.