No, stand that somes with it will not rotate. Only holds monitor up in landscape mode. To use in portrait mode you would need to get some type of stand with Vesa mount. Android HD portrait mode games run fine in full screen on it, but can only play them with Viewsonic in lap.
I use it all the time in portrait but I did buy a different mount. Only problem is the dumb compatibility filter that VS put on that prevents some portrait apps from play store. Most of these apps can be purchased elsewhere.