The portable collapsible self-assembling desk having a desktop, base unit, pivotal side supports, a tray and a lower shelf The desk in its collapsed configuration allows for easy transportation and storage and can be carried by a handle in a suitcase-like manner. The desk in its erected configuration provides a substantially horizontal work space. The pivotal side supports are automatically extended to provide support to the desktop allowing the desk to be easily converted between the collapsed and erected positions. These two configurations allow the desk to be in a collapsed configuration providing a small footprint and occupying substantially less space than when in the erect position.