Abstract: A break-down sofa having a frame that is adapted to be disassembled to facilitate transport and storage in a substantially flat shipping configuration. The frame of the sofa includes a seat platform to support the weight of a user, a front panel detachably connected to the front of the seat platform, opposing side panels detachably connected to opposite sides of the seat platform, and a back panel detachably connected to the back of the seat platform. To better enable the back panel to withstand a rearward pushing force applied thereagainst by a user who is seated upon the seat platform, complementary male and female interlocking members are moved into mating engagement with one another to hold the back panel in place between the opposing side panels.