Food intolerance is one of medicine's modern enigmas. Its etiology and mechanism are unclear and the subject of constant debate, while estimates of its prevalence vary widely from 2% to over 20% of the population. Using interpretive phenomenonological analysis, this study explored the phenomenon of food intolerance in primary care from the general practitioner's (GP) perspective. Semi-structured interviews were carried out with 17 GPs from around the UK. Food intolerance was primarily conceptualised as a spectrum of clinical importance with medical conditions arranged in three hierarchies; the certainty that the GP would have in making a diagnosis, the authenticity of the patients' experience, and the threat posed to physical health. Since some conditions within the spectrum had a medical name that was used in preference to the term 'food intolerance', food intolerance essentially became a 'dustbin diagnosis', focused at just one end of the spectrum and viewed with scepticism. The scepticism about food intolerance as a specific condition influenced the GPs' perceptions of patients and of the patients' underlying problems. This was, however, tempered by an element of awareness of the limitations of modern medicine. Rather than risk damaging the doctor-patient relationship, the GPs chose, despite their scepticism, to negotiate mutually acceptable ground with patients and with patients' beliefs. As a result, whether due to a placebo effect, secondary benefit, or as a biophysical result of excluding a food from the diet, the GPs acknowledged both personal and therapeutic benefit in working with the patients' belief in food intolerance and with behaviours associated with the beliefs.