The branching fraction of the decay B-s(0) -> D-s(()D-)+(s)(()-) is measured using pp collision data corresponding to an integrated luminosity of 1.0 fb(-1), collected using the LHCb detector at a center-of-mass energy of 7 TeV. It is found to be B(B-s(0) -> D-s(()D-)(s)(()-)) = (3.05 +/- 0.10 +/- 0.20 +/- 0.34)%, where the uncertainties are statistical, systematic, and due to the normalization channel, respectively. The branching fractions of the individual decays corresponding to the presence of one or two D-s(+/-) are also measured. The individual branching fractions are found to be B(B-s(0) -> D-sD-+/-(s)-/+) = (1.35 +/- 0.06 +/- 0.09 +/- 0.15)%, B(B-s(0) -> D-sD-+(s)(-)) = (1.27 +/- 0.08 +/- 0.10 +/- 0.14)%. All three results are the most precise determinations to date.