namespace-uri() function
File: Data.xml <?xml version="1.0" encoding="utf-8"?> <emailList> <head:header xmlns:head="http://www.domain.com/namespace/header"> <title>Email List</title> <maintainer>Joe</maintainer> </head:header> <person type="personal" id="p001"> <name>person1</name> <email>p@hotmail.com</email> </person> <person type="work" id="p002"> <name>person2</name> <email>p@hotmail.com</email> </person> <person type="personal" id="p003"> <name>person3</name> <email>p3@hotmail.com</email> </person> </emailList> File: Transform.xslt <?xml version="1.0"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:head="http://www.domain.com/namespace/header"> <xsl:output method="xml" indent="yes" /> <xsl:template match="/"> <xsl:apply-templates select="emailList/head:header" /> </xsl:template> <xsl:template match="head:header"> The namespace URI is: <xsl:value-of select="namespace-uri()" /> </xsl:template> </xsl:stylesheet> Output: <?xml version="1.0" encoding="UTF-8"?> The namespace URI is: http://www.domain.com/namespace/header