A new technique and instrumentation for hysteroscopy are described. After careful vagino-cervical antisepsis, the cervix is grasped pneumatically with the cannula at a negative pressure of 450 g. The cervical canal is dilated by insufflation of carbon dioxide, and the hysteroscope is advanced into the uterine cavity. (Cervical hemorrhage is avoided by dilation with gas.) The area of the tubal orifices is easily explored. It is expected that this method will be particularly useful in the diagnosis of uterine lesions and neoplasms.