A disposable hydrophilic catheterization device for inserting a hydrophilic catheter into the urethra of an individual for the purpose of evacuating the bladder is disclosed. The catheter device includes a catheter introducer, a flexible hydrophilic catheter and a flexible thin-walled sheath. The sheath surrounds the urethra-insertable portion of the catheter, is adapted for containing a wetting liquid, and prevents pooling of the wetting liquid with collected urine. A leak-resistant diaphragm disposed within the catheter introducer is capable of being pierced by the catheter tip to form a leak-resistant orifice around the wetted hydrophilic catheter as it moves through the orifice.
