Introduction and objective: Presentation of the Tansrectal method puncture of the undeflating Foley catheter balloon. Materiál and methods: Transrectal puncture of the Foley catheter balloon using the Franzen needle set is demonstrated in a concrete patient. To use this procedure, a simple instrumentarium comprising a digital needle introducer and flexible needle, current components of the Franzen needle set used for prostate aspiration cytological biopsy, is required. Results: The instrumentarium of Franzen needle enables effective and targeted puncture of the undeflating Foley catheter balloon. Conclusions: procedure is very simple and painless, so that ambulatory application is possible and no ultrasonography is required. Under ambulatory conditions the principle of a „protected" needle typical for the Franzen needle can be easily improvised.

        Key words: Foley catheter - undeflating balloon - Franzen needle - complications.