Three-dimensional (3D) imaging of vascular networks is essential for the investigation of vascular patterning and organization. Here, we present a step-by-step protocol for the 3D visualization of the vasculature within whole-mount preparations of the mouse intestinal muscularis propria layer. We then detail the quantitative analysis of the resulting images for parameters such as vessel density, vessel diameter, the number of endothelial cells, and proliferation. The protocol can be easily extended to study cell-cell interactions such as neuro-vascular or immune-vascular interactions. For complete details on the use and execution of this protocol, please refer to Schrenk et al. 1 .