A speculum insertable into a body cavity of a person including a support member having an opening, provided with elongated arm sections each disposed in a plane including a centerline of such opening, blade members each lying in the plane of an arm section and having an intermediate section pivotally connected to the support member, a first end section displaceable into and out of engagement with the end section of another blade member and a second end section displaceable relative to one of the arm sections, means for releaseably biasing the first end sections of the blade members into engagement, permitting such end sections to be inserted into and removed from a body cavity, and means mounted on each arm member, engageable by a second end section of a blade member, for camming such blade member to pivot about the axis thereof.