The catheter assembly includes a catheter having a catheter body, and a curved stylet that is constituted of a linear body of higher rigidity than the catheter body and is inserted into the catheter, the catheter assembly being assembled by inserting the curved stylet into the catheter. The curved stylet has a curved section, a part of which is curved. A deformation section that has been deformed in a curved manner along the curved shape of the curved section is formed on the catheter body at a portion where the curved section is located in the assembled state. The catheter assembly is so configured that, when the catheter is inserted into the urethral lumen in the assembled state, the deformation section curves a portion of the urethral lumen that faces the deformation section.
