This paper explores the relationship between fundamental quarks in a gauge theory and D-branes in the dual AdS/CFT correspondence. It shows that adding fundamental quarks corresponds to introducing space-time filling D-branes in the dual 5D closed string background. These D-branes must be able to end in thin air to account for massive quarks, which live in the UV region. They must also come in distinct sets to represent the chiral global symmetry, with a bifundamental field playing the role of the chiral condensate. The paper demonstrates that these expectations are satisfied in several supersymmetric examples. The paper discusses the probe limit, where the backreaction of the flavor D-branes on the bulk geometry is neglected. It shows how to introduce space-time filling branes without running into contradictions with tadpoles. The D-branes are stabilized by negative mass modes, which control their slipping off the cycle they wrap, but are not negative enough to lead to instability in the curved 5D geometry. The paper also shows how to read off the cycle wrapped in the internal manifold and the worldvolume scalars that are turned on from knowledge of the embedding in the flat 10D spacetime. The paper also discusses the global symmetry of the theory, showing that the spacetime filling D-branes come in two distinct sets, giving rise to chiral SU(M) × SU(M) global symmetry. It shows how this is reproduced in the bulk by having two distinct spacetime filling sets of branes, which differ by the cycle they wrap in the internal space. The paper also discusses the supersymmetry of the D-branes, showing how to verify that all solutions are supersymmetric by analyzing κ-symmetry on the worldvolume. The paper concludes by discussing the implications of these results for the study of non-perturbative superpotentials in SQCD. It shows that the results can be applied to a variety of theories, including pure N=2 with N=1 preserving fundamental matter, and non-supersymmetric large N QCD. The paper also discusses the chiral condensate, which corresponds to a nontrivial profile for the bifundamental scalar, and the meson-spectrum, which can be read off from the discrete eigenmodes of the worldvolume gauge fields.This paper explores the relationship between fundamental quarks in a gauge theory and D-branes in the dual AdS/CFT correspondence. It shows that adding fundamental quarks corresponds to introducing space-time filling D-branes in the dual 5D closed string background. These D-branes must be able to end in thin air to account for massive quarks, which live in the UV region. They must also come in distinct sets to represent the chiral global symmetry, with a bifundamental field playing the role of the chiral condensate. The paper demonstrates that these expectations are satisfied in several supersymmetric examples. The paper discusses the probe limit, where the backreaction of the flavor D-branes on the bulk geometry is neglected. It shows how to introduce space-time filling branes without running into contradictions with tadpoles. The D-branes are stabilized by negative mass modes, which control their slipping off the cycle they wrap, but are not negative enough to lead to instability in the curved 5D geometry. The paper also shows how to read off the cycle wrapped in the internal manifold and the worldvolume scalars that are turned on from knowledge of the embedding in the flat 10D spacetime. The paper also discusses the global symmetry of the theory, showing that the spacetime filling D-branes come in two distinct sets, giving rise to chiral SU(M) × SU(M) global symmetry. It shows how this is reproduced in the bulk by having two distinct spacetime filling sets of branes, which differ by the cycle they wrap in the internal space. The paper also discusses the supersymmetry of the D-branes, showing how to verify that all solutions are supersymmetric by analyzing κ-symmetry on the worldvolume. The paper concludes by discussing the implications of these results for the study of non-perturbative superpotentials in SQCD. It shows that the results can be applied to a variety of theories, including pure N=2 with N=1 preserving fundamental matter, and non-supersymmetric large N QCD. The paper also discusses the chiral condensate, which corresponds to a nontrivial profile for the bifundamental scalar, and the meson-spectrum, which can be read off from the discrete eigenmodes of the worldvolume gauge fields.