This study examined the abrasion and mechanical properties of poly(ethylene terephthalate) (PET) flameretardant fabrics used for window coverings. The tensile linearity, tensile resilience, bending rigidity, bending hysteresis, shearing stiffness, shearing hysteresis, compression energy, and surface roughness all increased with increasing fabric density and cover factor ratio. Five samples were subjected to more than 16,000 cycles for the abrasion resistance test and to grade 4 for the snagging test. The drape test showed that the flexibility of the samples was affected by fabric density and cover factor ratio.