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Barley (Hordeum vulgare L.) is a highly adaptable cereal crop grown under a wide range of agro-ecological conditions. Various literature reports demonstrate that heterozygosity may enhance the yielding level and stability of barley particularly in stress-prone environments. The major aim of this study was to investigate whether recurrent selection (RS) for heterozygosity at highly polymorphic codominant molecular marker loci increases outcrossing in a genetically broad-based population. Four to six SSR marker loci were used for this purpose. Selection was conducted over four cycles. Progress from selection was evaluated in a terminal experiment comprised of population samples from all four RS cycles. All experiments were conducted under greenhouse conditions. The starting population was composed of 201 gene bank accessions (178 lines, 12 landraces and 11 wild barley populations) sampled in West Asia and North Africa. Selection led to a stepwise increase in heterozygosity from 0.23% to 1.50%. Correspondingly, the estimated multilocus outbreeding rate rose from 1.4% to 3.5%. This positive selection response offers new perspectives for improving the productivity of barley in stress-prone areas.