We report the first measurement of the branching fraction for the inclusive decay B-->X(s)l(+)l(-), where . is either an electron or a muon, and X-s is a hadronic recoil system that contains an s quark. We analyzed a data sample of 65.4x10(6) B meson pairs collected with the Belle detector at the KEKB e(+)e(-) asymmetric-energy collider. We find B(B-->X(s)l(+)l(-))=[6.1 +/-1.4(stat) (+1.4)(-1.1)(syst)]x10(-6) for dilepton masses greater than 0.2 GeV/c(2).