Less than one thousand years dating of the youngest volcanic episode of the Teide volcano (Canary Islands, Spain) has been performed using the K/Ar Cassignol technique. Analyses of about 20 g of pure alkali-feldspar yielded a weighted mean age of 800¿300 years. Stratigraphic, historic and archeomagnetic dating validate this age and rule out the hypothesis of the presence of significant excess argon contamination for this flow. Our result shows that the last effusive activity of the Teide volcano took place shortly before European settlement in Tenerife Island. This study confirms that the Cassignol technique can be applied with success for historic dating and demonstrates that it can now even be extended to the last millennium. ¿ 2001 American Geophysical Union