A catheter assembly with a catheter and a package for a catheter are provided. The package and catheter is provided with a seal that restricts passage of fluid between the package and the catheter. The assembly allows the catheter to be used without complete removal from the package. During urination, the assembly prevents the flow of urine from the outlet of the catheter and back through the package in a direction towards the user of the catheter. The seal allows the catheter to be dispensed from the package while the sealing is maintained and the assembly thus allows non-contaminated insertion and use of the catheter while the catheter is partly maintained in the package.