Fourteen healthy volunteers were examined using rhinostereometry (RSM) and micromanipulator-guided laser-Doppler flowmetry (LDF) on the inferior turbinate and nasal septum. There were significant differences of the flowmetry readings at different distances from the mucosal surface within 0-1.0 mm. Changes in LDF values due to a change in distance between probe and mucosa seem to be an important artefact that will influence the flowmetry, especially if the probe is fixed to the framework of the nose (i.e. the skull) and if the congestive status of the mucosa changes. This can be a problem especially during intranasal challenges with substances that influence congestion. These artefacts can be eliminated by using an RSM-guided micromanipulator that allows the probe to follow changes in congestion.