Abstract: A frame assembly for a free-standing portable shelter comprises a plurality of tubular frame members releasably interconnected by a system of connector fittings. Leg and eave members are provided with spring-loaded projecting members which releasably engage corresponding apertures in unitary corner and eave fittings; rafter members include slotted locking collars connectable at one end to bar-type coupling means on eave and corner fittings, and at the other end to a central anchor member. Leg braces are mounted between leg and eave members by spring pins for additional support. The structure may be assembled and disassembled quickly and entirely without the use of tools.