The self-assembly of folic acid solutions at low concentrations, which has implications in its possible use as a drug delivery carrier, is presented. X-ray diffraction (XRD) is used to show that folic acid has ordered structures in solution at concentrations lower than 1 wt %, but only in its ionized state. Various microscopy techniques and rheological studies are used to show existence of different phases of the ordered structures in the solution phase as well as the properties of this complex fluid. In conjunction with semiempirical calculations and molecular dynamics simulations, the XRD studies help to understand the mechanisms of formation of the ordered phase as well as the structure in solution. (C) 2013 American Institute of Chemical Engineers AIChE J, 59: 1360-1368, 2013