Montecatini Terme, emblematic city for the close combination between thermal baths and urban structure, has been recently enrolled in the list of the Unesco Heritage. It becames particularly urgent to deepen the knowledge, in an appropriate way, of the building ensemble that can be considered the key features in the enrollement, for the purposes of their protection and safeguard. Among these, the Tettuccio bath assumes a particular relevance with regard to the complex architectural articulation, the richness of the decorative characteristics and the variety of the materials used. For this purpose, a laser scanner survey combined with photogrammetry was carried out, thus obtaining a high level of instrumental data, integrated by accurate in-place information. This approach highlighted the materials, traditional and modern, and the decay of the building, founded by the grand duke Pietro Leopoldo and almost completely refashioned about a century ago.