Abstract: A foldable portable crib comprises a pair of opposing side assemblies and a pair of opposing end assemblies supporting a mattress therebetween to form a crib frame. A mattress support platform is pivotally mounted to a pair of first corner posts, and moveable from an open, generally horizontal position to a folded, generally vertical position. In the folded position, the mattress support platform is positioned from a first side assembly a sufficient distance to stow a mattress and detached second side assembly therebetween. A portion of the end assembly is pivotally moveable about first corner posts for folding against the mattress support platform. A curved hinge joint and hinge brackets are provided for enhanced stability of the crib in its open, usable position. In the folded position, the portable crib is in a unitary, compact, and freestanding configuration.