Purpose The skin microvasculature is important in supporting wound healing of diabetes-related ulcers. However, current imaging methods (ultrasound, laser doppler, MRI) are unable to directly visualise and quantify changes in these vessels (diameter 30 – 100 microns). This study demonstrates the use of a new imaging method to directly visualise changes in microvascular structure and function. Methodology We developed a novel medical imaging scanner using optical coherence tomography (OCT) to perform non-invasive imaging of the microvasculature in the dermis of the foot. The scanner was placed directly onto the intact skin and automated analysis software quantified changes in the optical signal to identify the diameter and flow speed in individual vessels within a 5 x 5mm field of view. Two co-located scans were acquired, one showing baseline flow at room temperature (32 degrees C), and a second showing vasodilated flow after 20 minutes of localised heating of the skin at 42 degrees C. Results Scans of healthy volunteers showed an intricate network of skin microvessels, and increases in vessel diameter, flow speed and vessel density after localised heating. Scans of people with diabetes, with foot oedema, showed almost no microvascular flow, but some flow in larger microvessels (> 100 microns). We observed an increase in flow in these larger vessels of patients with diabetes after localised heating. Pre- and post-surgery scans of a patient undergoing popliteal and tibial angioplasty showed a large increase in microvascular flow at 2 weeks post-surgery. Conclusion OCT allows visualisation and quantification of changes in the skin microvasculature. This has the potential to quantify the impact of microvascular flow on wound healing outcomes for diabetes-related foot ulcers, providing additional information for improved patient management.