This review of laser Doppler flowmetry (LDF) focuses on indications and limitations in general and the author's experience of LDF in the assessment of tendon perfusion in particular. LDF is easy to use, minimally invasive and well suited for the study of relative changes in perfusion during rapid events. Problems specifically related to LDF include motion artifacts, a non-flow dependent output of unknown significance and uncertainty regarding the spatial resolution. The human Achilles tendon has a lower perfusion at the insertion but otherwise an even distribution of blood flow. Male gender, advancing age and mechanical loading of the tendon are associated with diminished tendon blood flow. The lesion in chronic degenerative Achilles tendinopathy is associated with hyperemia of uncertain origin.