Current polyamide 11 and 12 are lacking in fire retardancy and high strength/high heat resistance characteristics for fabricated parts that are required for performance driven applications. The introduction of selected nanoparticles such as carbon nanofibers (CNFs), combined with a conventional intumescent flame retardant (FR) additive into the polyamide 11/polyamide 12 (PA11/PA12) by melt processing conditions has resulted in a family of intumescent polyamide nanocomposites. These intumescent PA11 and PA12 nanocomposites exhibit enhanced polymer performance characteristics, i.e., fire retardancy, high strength, and high heat resistance and are expected to expand the market opportunities for resin manufacturers. The overall objective of this research is to develop improved PA11 and PA12 polymers with enhanced flame retardancy, thermal, and mechanical properties for selective laser sintering (SLS) rapid manufacturing. Arkema RILSAN® PA11 polymer was examined with CNFs and Clairant Exolit® OP 1230 intumescent FR additive. They were used to create a family of FR intumescent PA11-CNF nanocomposites. Transmission electron microscopy (TEM) was used to determine the degree of CNFs and intumescent FR additive dispersion in PA11. Injection molded specimens were fabricated for material properties measurements. Thermal stability of these polymer nanocomposites (PNs) was examined by TGA. Flammability and thermal properties of these PNs were obtained using the cone calorimeter, UL 94 test method, and heat deflection temperature.