Clay-polyimide [3,3', 4,4'-benzophenone tetracarboxylic dianhydride-4,4'-oxydianiline (BTDA-ODA)] nanocomposites were synthesized from ODA-modified montmorillonite (organoclay) and poly(amic acid). The layered silicates of organoclay were intercalated by polyimide (BTDA-ODA), as confirmed by X-ray diffraction and by transmission electron microscopy, and the tensile mechanical properties of the nanocomposites were measured. It was found that the modulus and the maximum stress of these organoclay/BTDA-ODA nanocomposites were much higher than those of pure BTDA-ODA: a twofold increase in the modulus and a one-half-fold increase in the maximum stress in the case of 7/93 organoclay-BTDA-ODA. In addition, the elongation-for-break of organoclay/BTDA-ODA nanocomposites is even slightly higher than that of pure BTDA-ODA, which is a sharp contrast to that of conventional inorganics-filled polymer composites.