Delays in the diagnosis of cancer are common, and they are attributed to both patient and healthcare system factors. Minimizing such delays and improving early detection rates is a key goal of the new cancer reform strategy in England, in light of recent data showing that survival rates in the UK are low. The aim of this study was to explore the pathway from initial persistent change in health to diagnosis of cancer in a sample of patients from seven diagnostic groups in the UK and the factors mediating this process. Qualitative interviews with patients diagnosed with cancer were carried out. Seventy-five cancer patients discussed their pre-diagnosis experience as part of a broader exploration of their symptom experience for a larger study. Data were analysed by using content analysis and chart events. A broader range of mediating factors affecting and extending the patient pathway to diagnosis were reported in relation to lung, gastrointestinal and head and neck cancers and lymphoma, compared with breast, gynaecological and brain cancer patients. Many of the mediating factors were patient-related (e.g. misattribution of symptoms to common ailments, underestimation of the seriousness of the symptoms, self-medication or monitoring of symptoms, etc.). Primary care practitioner-factors were also prominent, including the exploration of firstly more common possibilities for treating the presenting symptoms without follow-up of persisting symptoms. Public health education about common cancer signs and symptoms, educational approaches in primary care to improve early diagnoses of cancer and updated guidelines for referral of suspected cancers should be enhanced before we can see any improvements in survival rates from cancer in the UK.