A small group of opaque yellow glazed sherds has recently been identified among the ceramics excavated at the Islamic city of Madīnat al-Zahrā' near Cordoba, in al-Andalus (southern Spain), which was founded in 936 AD as the seat of the Umayyad Caliphate power. A small group of sherds from Madīnat al-Zahrā', which can be dated to about 960-980 AD, have been examined in polished section in a SEM with EDS attached. These analyses have established that the Madīnat al-Zahrā' sherds were opacified with lead stannate, and not lead antimonate, as was being used to opacify yellow glazed ceramics in Egypt and Tunisia in the 9 th and 10 th centuries AD. Islamic opaque yellow glazed ceramics, with lead stannate as the opacifier, were first produced (Watson 2014), in Egypt and Syria in 7 th /8 th centuries AD, and from there the technology spread eastwards into Iraq and Iran in 9 th century AD, and continued in use in Iran and Central Asia into the 10 th century AD and beyond. However, the question of where these opaque yellow glazed ceramics were produced has not been fully resolved. Because such ceramics are extremely rare in al-Andalus, it seems most likely that they were either imported from Iran or Central Asia, or produced locally by potters arriving from these areas. The study adds one further, yet not fully understood chapter to the story of a persistent glaze technology which has been widely ignored.