In Android m5 rc15, nested XML is not possible. Google should have included this feature because it is very useful. You don’t have to clutter your layouts inside 1 XML file. As with other web programming languages where you can do includes, Android doesn’t have it. So far, there has been no workaround made. I came upon one person who gave a solution but somehow it didn’t work. I always have this “layout_width must be set” problem. You can however load XML layouts at runtime using the ViewInflate class. But you need to have layout tags in your XML files and retrieve them via your code. For a quick sample, I had a separate article regarding this.