Mono and difunctional polystyrenes containing active halogenated end groups were prepared by atom transfer radical polymerization (ATRP). Substitution reactions were explored to convert the halogen termini to azido groups, followed by reduction to form the amino functional polymer. Quantitative conversion of the end groups was observed in each transformation reaction. H-1 NMR demonstrated the formation of the azide from the bromide functionality without elimination. The difunctional alpha,omega-diaminopolystyrene was reacted with terephthaloyl chloride in a condensation process to produce chain-extended polystyrene containing amide bonds along the polymer backbone.