We report the facile synthesis of well-defined ABA poly(lactide)-block-poly(styrene)-block-poly(lactide) (LSL) triblock copolymers having a disperse poly(styrene) midblock ((D) over bar = 1.27-2.24). The direct synthesis of telechelic alpha,omega-hydroxypoly(styrene) (HO-PS-OH) midblocks was achieved using a commercially available difunctional free radical diazo initiator 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide]. Poly(lactide) (PLA) end blocks were subsequently grown from HO-PS-OH macroinitiators via ring opening transesterification polymerization of (+/-)-lactide using the most common and prevalent catalyst system available, tin(II) 2-ethylhexanoate. Fourteen LSL triblock copolymers with total molar masses M-n,M-total = 24-181 kg/mol and PLA volume fractions f(PLA) = 0.15-0.68 were synthesized and thoroughly characterized. The self-assembly of symmetric triblocks was analyzed in the bulk using small-angle X-ray scattering and in thin films using grazing incidence small-angle X-ray scattering and atomic force microscopy. We demonstrate both the bulk and thin film self-assembly of LSL disperse triblocks gave well-organized nanostructures with uniform domain sizes suitable for nanopatterning applications.