Abstract: A catheter assembly which includes a catheter having a flexible, preformed distal end and a sheath slidably mounted thereon. The sheath can be slidably moved from a first position with the sheath overlying a portion of the catheter that is not precurved to a second position with the sheath overlying the precurved distal end in order to straighten the catheter for insertion and removal from a body cavity. When the catheter assembly is introduced into a body cavity, the distal end of the catheter is removed from the sheath in order to allow it to assume its preshaped form and thereby serve to retain the catheter. The distal end of the catheter is withdrawn into the sheath in order to remove the catheter from a body cavity.