We consider effective actions for six-dimensional noncritical superstrings. We show that the addition of N units of RR flux and of Nf space–time filling D5-branes produces AdS 5×S1 solutions with curvature comparable to the string scale. These solutions have the right structure to be dual to [Formula: see text] supersymmetric SU (N) gauge theories with Nf flavors. We further suggest bounds on the mass-squared of tachyonic fields in this background that should restrict the theory to the conformal window.