Abstract: A speculum having a dilator for insertion into a body cavity of a patient and an opening mechanism for opening the dilator to dilate the body cavity. The dilator has at least two dilator blade members which are pivotal. The opening mechanism consists of a collar which is rotatable to contact and bear against the blade members. This causes the blade members to pivot and move apart, thereby opening the dilator. This results in the body cavity of the patient being dilated which allows for easy examination thereof.