Biliary stents are used to treat obstructions that occur in the bile ducts. The stents can be blocked by new tissue in a few months after their implanting. This complication can be solved by using radiofrequency ablation. The present article deals with monitoring of the process of monopolar thermoablation of a metal stent by using an infrared camera ex vivo. The metallic EGIS Biliary stents 10mm×80mm were used in experiments; radiofrequency ablation due by catheter EndoHPB 8F at 460kHz was used. The Flir B200 thermocamera was used for monitoring. The results show an increase in temperature of the stent's material during thermoablation process. It is believed that the metal stent becomes an active electrode. The results show an increase in temperature of the stent and the surrounding tissue during the treatment. Temperature distribution measured on stent was affected by power applied and obviously non-homogeneous. The maximum temperature values were observed at the ends of the stent. The temperature value of the stent during termoablation depended also on the position of the second (inactive) surface electrode. Results of this study have shown that there are many factors able to affect the final temperature or process of tissue ablation inside of the stent and around the stent. Infrared camera seems to be an appropriate instrument for observing the distribution and changes in temperature during ex vivo radiofrequency ablation.