This paper investigates hygro-thermally curvature-stable (HTCS) antisymmetric laminates with extension-twist coupling. Stacking sequences are designed to obtain optimal extension-twist coupling and buckling strength. A new objective function that maximizes both extension-twist coupling and buckling strength is established by using the weighted sum method. Multi-objective optimization of HTCS antisymmetric laminates is performed for T300/976 graphite/epoxy laminates. Results are presented for the laminates that consist of 6-14 even plies. The effects of the weighting coefficients on the extension-twist coupling and buckling load are analyzed. The robustness of the optimization method is verified by using Monte Carlo simulation for laminates with fiber orientation that slightly deviates from the theoretically designed direction.