Abstract: A process for production of a dimensionally stable drawn polyethylene terephthalate multifilament yarn having filaments of at least 2.5 denier per filament comprising the steps of:a) extruding a polyethylene terephthalate polymer melt through a spinnerette having a plurality of extrusion orifices to form filaments;b) advancing the extruded multifilament yarn first through a delay zone then through a quenching zone to solidify the filaments in a controlled manner;c) withdrawing the solidified multifilament yarn from the quenching zone at a desired spinning speed V;whereby steps a) through c) are performed under conditions to form a partially-oriented multifilament yarn having a undrawn birefringence (.DELTA.n.sub.u) of at least 0.020 and wherein .DELTA.n.sub.u =R.sub.f V.sup.2.0 IV.sup.2.4 where IV is the intrinsic viscosity of the undrawn yarn and is at least 0.80 and R.sub.f is at least 9.0.times.10.sup.-3 ; thend) hot drawing the partially-oriented multifilament yarn.