Diagnostic biopsy specimens from six posterior orbital lesions have been obtained under direct endoscopic view with either a fine needle aspiration or an intracannular microbiopsy forcep. This method is comparable to earlier fine needle aspiration techniques, but has the decided advantage of providing a specimen from visually indentified abnormal tissue. In those cases where inadequate specimens are obtained by fine needle aspiration, a rnicroforcep is used to obtain a substantial specimen. The microinvasive endoscopic biopsy technique of the Orbital Unit at Pacific Medical Center is described with an analysis of six cases. The emerging technology of fiberoptic illumination, minified color video cameras, sophisticated imaging, efficient microsurgical instruments and laser delivery methods make the potential for deep orbital endoscopic microinvasive surgery exciting.