This contribution describes a simple, aerosol-based method for fabricating monodisperse particles containing mixtures of poly(lactide-co-glycolic acid) [PLGA], protamine sulfate (Prot), and poly(l-lysine) [PLL] as nanocarriers for gene transfection. Aqueous solutions of PLGA, Prot, and PLL were collison-atomized, and the resulting aerosolized droplets were dried on the fly to form solid particles, which then were electrostatically size-classified into 50, 100, and 200 nm mobility diameter samples. Measurements of cell viability and transfection reveal that the fabricated nanocarriers have a lower cytotoxicity (>85% in cell viability) and a higher transfection efficiency [>8.7 x 10(5) in relative light units (RLU) mg(-1)] than does 25 kDa polyethyleneimine (approximate to 50% and 6.8 x 10(5) RLU mg(-1)).