Effect of disperse dyeing on flame retardant finishing of PET fabrics via UV curing using three UV curable phosphorous-containing methacrylates and ammonium polyphosphate(APP) was investigated. The dye fixation and flame retardancy of PET fabrics did not change significantly with excellent durability to five laundering cycles irrespective of the dyeing and finishing sequence. However, the flame retardancy of Pekoflam-treated fabrics was lower than that of the UV treated and decreased substantially when heat treatment was carried out before the dyeing. The dyeability of the flame-retardant PET fabrics was not affected in the case of UV curing of the methacrylates alone. However, UV finishing after the dyeing caused significant decrease in K/S and ${Delta}E$ due to changed refraction and inherent color of surface coating of the UV curable monomers and APP. Whereas the heat treatment with Pekoflam decreased both color fastness to laundering and sublimation, surprisingly the UV finish of PET fabrics before and after the dyeing increased the color fastness probably resulting from the presence of photopolymerized surface layer on the fabrics.