Abstract: A modular furniture system is disclosed which consists of functional modules that can be oriented, stacked and interlocked to create different furniture assemblies. The modules include identical rectangular enclosures, one of which contains drawers and another a cupboard and retractable writing surface. The enclosures can be stacked one on top of the other with a portion of the uppermost enclosure supporting one end of an upper bunk bed module. Another support means supports the other end of the bunk bed. An apparatus is also disclosed for interlocking the stackable enclosures and the upper bunk bed end to the uppermost enclosure. A removable cover is provided for the exposed portion of the uppermost enclosure adjacent the end of the bunk bed. By varying the width of the removable cover, a shelf of variable area can be provided. One end of a lower bunk bed module can be positioned within the enclosure formed by the upper bed and its two end supports.