While non-destructive 3D technologies offer outstanding possibilities for analysing shape and similarities in architectural details, and for the monitoring of weathering effects, it has so far been used only rarely for these purposes. This paper shows the application and analysis of high resolution, handheld, optical tracked laser scanning on an inscription at the cathedral of Notre Dame in Paris. The transept’s south façade carries a latin inscription dating from 1258, and the common research opinion is that the inscription was copied and renewed during the mid-19th century restoration. In the course of an on-site research campaign, some doubt as to the veracity of this theory arose. Essential questions regarding the inscription concern the workflows of both medieval craftsmen and those from the 19th century. The project’s aim was to analyse the inscription for its shape and for any traces left by the craftsmen. Another key question focussed on the originality and authenticity of the inscription. The analysis of the high-resolution 3D data set has confirmed the initial visual impression of differences between the stones and shown that most of the inscription is the 13th century original with only a few parts replaced. The analysis also revealed that the ribbon and the letters must have been carved before the stones were placed. An investigation using historical transcripts, comparative examples and contextual reflections with a detailed analysis of the individual letters also revealed possible changes in the wording of the inscription made during the restoration. A discussion of the possible variants supported by virtual visualisations is also presented.