Proceeding of the Joint International Symposium on Deformatuon Monitoring. 2-4 November, 2011. Hong Kong. China. Report. This paper presents an innovative procedure for the analysis of vertical movements of a structure. Here, the focus is on tunnel monitoring and especially on underground lines, where all measurements need to be rapidly carried out during the night, when traffic is stopped. The main concept is the substitution of optical geometric leveling, based on levels and rods, with an image-based solution coined "photogrammetric leveling". The proposed method is notably quicker and more economical. A calibrated digital camera is adopted to capture an image of two special rods placed (or hung) on a pair of height benchmarks. Some targets on the rods are used to determine the vanishing line, that is then used to rectify the image. The knowledge of the distances between opposite targets is used to remove a final scale ambiguity. This allows the estimation of the height differences between the benchmarks by using just one image. Several tests with synthetic and real data were performed to check the accuracy of the method. In addition, some theoretical, practical and numerical results, along with the advantages, limitations, and failure cases of the photogrammetric leveling approach are addressed.