A two step procedure was employed to prepare a colloidal scale, uniform dispersion poly(p-aminobenzoic acid) (PAB) in Nylon 6(3)T. In the first step, a colloidal suspension of PAB was prepared via direct polycondensation, starting from a concentrated solution of AB in dimethyl acetamide (DMAc) containing suitable activators. In the second step, a solution of Nylon 6(3)T in DMAc was mixed with the colloidal suspension. The composite powder was generated by precipitation in water and the composite film obtained by redispersing the powder in DMAc and casting. The films contain PAB particles, below 100 nm in size, uniformly distributed in the Nylon 6(3)T matrix. The mechanical properties and the thermal transitions of these composites were investigated.