Abstract Intercomparison measurements have been carried out by twelve manufactures of form measurement equipment, industrial users and national metrology institutes to determine the present-day agreement in form measurement at an accuracy level of approximately 0.1 μm and to formulate ways to improve agreement. This work has been supported by the Commission of the European Communities under its programme for Applied Metrology and Chemical Analysis (BCR). All participants measured two cylindrical artefacts to determine the deviations from roundness, straightness, parallelism and cylindricity. The artefacts were chosen to have some roundness and straightness deviations comparable to the guide errors of the instruments used (up to 0.5 μm) as well as other characteristic form deviation features (up to 15 μm), allowing the amplification and transmission properties of the instruments to be investigated. Satisfactory agreement of the participants' results has been observed with respect to roundness and straightness, whereas large variations have been found in parallelism and cylindricity, where the position and form deviations of several measuring lines are taken into account to evaluate quantities. It is recommended that future efforts to achieve a higher degree of accord of form measurement should concentrate on the different techniques used for transducer calibration and the different characteristics of the software filter applied.