Aims and Objectives: To evaluate the influence of metal framework design on fracture strength, marginal adaptation and nano leakage of three designs of metal ceramic inlays. Materials and Methods: Three designs for metal ceramic inlays with different metal framework extension were studied: Group A - metal extension on all cavity walls, Group B- on all cavity walls but 1.5mm below cavo-surface margin, Group C- on pulpal, axial and ginigival walls. Empress 2 all-ceramic inlays were used as controls (Group D). The fabricated inlays were cemented into standardized resin teeth using adhesive resin cement.