The effect of cooling rate on residual stress development in a graphite/thermoplastic matrix composite was studied by monitoring warping of an unsymmetric cross-ply laminate. Being amorphous, the thermoplastic resin showed only a minimal sensitivity to the cooling rates employed. The residual stresses at room temperature were high enough to cause ply cracking. Therefore, the effect of transverse crack on the curvature was evaluated by using a modified stiffness model based on the classical laminate theory.