ProblemThe objective of this study was to develop a useful and cost‐effective olfactometer for routine clinical use. The apparatus was developed to provide a standardized threshold test for patients with olfactory disorders presenting in the ENT clinic.MethodsA prospective study of olfactory thresholds in 48 healthy volunteers on 2 consecutive occasions, undergoing quantitative testing with an olfactometer. Further studies of 10 subjects performing 20 tests and 100 subjects performing a single test were also performed. An olfactometer was designed to deliver a semi‐automated threshold test for an odor. It was designed as a device containing 8 logarithmic dilutions of an odor along with a control valve operated by software from a laptop computer. Common potential variables for olfactory threshold testing were considered including peak inspiratory flow rate and smoking status. The odors used for the studies were phenethyl alcohol (PEA) and eucalyptol. Subjects were asked to perform 2 tests within 1 month of each other and the mean threshold score for each test was calculated to help derive a test‐retest score.ResultsConsistent olfactory thresholds for PEA were achieved with a mean concentration of 10–4. Test‐retest reliability scores for the olfactometer were rx = 0.78 (95% CI 0.67 to 0.89). Common variables thought to affect olfactory testing including peak inspiratory flow rate and smoking were not found to have a significant effect on the threshold scores.ConclusionThe Leicester Olfactometer provides a simple and cost‐effective method of reliably assessing olfactory thresholds in the outpatient clinic.SignificanceRoutine testing of olfaction can be provided with a sophisticated yet user friendly format that overcomes the expense of single use test kits and other commercially available kits.SupportDepartmental research funds used.