BACKGROUND: Optical coherence tomography (OCT) is a recently developed compact technology which uses infrared light to perform cross-sectional imaging on a micrometer scale. Since OCT provides imaging at a resolution comparable to conventional histology and does not require direct contact with the tissue surface, a role in real-time surgical diagnostics represents a logical extension. In this work, we test the feasibility of OCT for surgical diagnostics by demonstrating imaging in tissue relevent to microsurgical intervention, a previously undescribed observation. MATERIALS AND METHODS: Over 50 sites on nervous, reproductive, and microvascular specimens from 10 patients were examined postmortem with OCT. After imaging, tissue was registered with microinjections of dye, under visible light laser guidance, followed by routine histologic processing to confirm the identity of microstructure. RESULTS: The 16 +/- 1 microm resolution allowed subsurface microstructure to be identified at unprecedented resolution. Structures identified included fascicles of peripheral nerves, the internal elastic membrane of microvessels, and the granular layer of the cerebellum. CONCLUSIONS: The ability of OCT to provide micrometer-scale definition of tissue microstructure suggests a role in surgical diagnostics. Future in vivo investigations are merited to establish its utility for morbidity reduction associated with surgical intervention.