A catheter placement device is provided which includes an adapter with an elastomeric grommet having a bore through which a pliable catheter is fed into a blood vessel of a patient. The grommet has a flange engageable with the catheter and effects a relatively low resistance to distal movement of the catheter and relatively high resistance to proximal movement of the catheter. A pair of adapters may be used with one adapter carrying a grommet and the other having a frusto-conical bore receiving an end of the grommet. The adapters are relatively rotatable to cause the grommet to lock the catheter against axial movement relative to the adapters. Retention members may be used to prevent inadvertent separation of the adapters during relative rotation.