Description of the problem: We investigate the use of spatially resolved diffuse reflectance spectroscopy for skin ageing assessment by focusing on type I collagen as skin chromophore and scatterer. Method of study: Measurements were carried out with a home-made dedicated probe, on the one hand, on 3D collagen matrices, and on the other hand, on several volunteers' skin. Matrices were reconstructed using collagen extracted from rat tail tendons. Animals of two different ages (young and old adults) were considered. Results: In vitro acquisitions show great differences between old and young adults collagen. Analysis of the in vivo study gives a more subtle trend. More results are consequently needed to conclude. Conclusions: According to the in vitro results, diffuse reflectance signal of type I collagen appears as a relevant marker for skin ageing assessment. The interpretation of the in vivo scattering spectra in comparison with in vitro results is under investigation to complete the in vivo conclusions.