BACKGROUND: The aim of the paper was to explore the experiences of people with gastrointestinal cancer within the first year following their diagnosis. The main objective was to contextualise and map the experiences of this cancer population over the first year following diagnosis to determine the indicators of change so that these patients might be supported at the most appropriate time points. METHODS: A qualitative longitudinal study design using semistructured interviews was adopted for this study with a heterogeneous sample of 18 patients with gastrointestinal cancers. Interviews were conducted on four time points over the first year providing a total of 60 interview datasets. RESULTS: Five key themes generated from the analysis including symptoms; impact of symptoms on everyday life; return to work and survivorship; impact on sense of self, and fear and uncertainty. CONCLUSIONS: These findings provide important insight into the process of change which occurs over the first year following diagnosis and enhances our understanding of the most appropriate time points for support.