Aims: To assess the route to secondary care for patients with possible occupational asthma, and to document the duration of workrelated symptoms and referral times.Methods: Consecutive patients with suspected occupational asthma were recruited to a case series from six secondary care clinics with an interest in occupational asthma. Semi-structured interviews were performed and hospital case notes were reviewed to summarise relevant investigations and diagnosis.Results: 97 patients were recruited, with a mean age of 44.2 years (range 24-64), 51 of whom (53%) had occupational asthma confirmed as a diagnosis. Most (96%) had consulted their general practitioner (GP) at least once with work-related respiratory symptoms, although these had been present for a mean of 44.6 months (range 0-320 months) on presentation to secondary care. Patients experienced a mean delay for assessment in secondary care of 4 years (range 1-27 years) following presentation in primary care.Conclusions: Significant diagnostic delay currently occurs for patients with occupational asthma in the UK.