X-ray absorption fine structure (XAFS) measurements have been made at the Cs Lm absorption edge on (1) 0.04 M acetonitrile solutions with respect to both CsBr and dibenzo-18-crown-6 ether (Cs-D18C6), (2) solids produced by drying the aforementioned Cs-D18C6 solution complex, and (3) crystalline CsBr, CsCl, and CsF powders that were used as standards, XAFS measurements have also been made at the Br M absorption edge on the same 0.04 M solution mentioned above. Due to the many difficulties associated with obtaining high-quality XAFS data on these systems, a custom-manufactured 5-mil-thick Sc foil was used in conjunction with a Seller slit assembly to improve the XAFS signal-to-noise ratio by almost a factor of 6, XAFS analyses of the Cs-D18C6 solution show the presence of a 1:1 Cs-D18C6 complex with a Br contact ion, consistent with previous references derived from Cs-133 nuclear magnetic resonance investigations. For interpretation of the Cs LIII edge data, the choice of a Br counterion reduces the error in determining the presence of a single counterion among the lighter backscattering O and C atoms of the crown ether complex. Observation of the normalized XAFS data for the dried Cs-crown ether solution shows that the Cs atom’s local environment changes from a 1:1 Cs-D18C6 complex to a predominantly crystalline CsBr solid phase. This recrystallization during drying illustrates the importance of in situ methods to characterize chemical speciation in solution. The ability of XAFS to directly probe the ternary Cs-D18C6-Br contact ion pair opens many exciting avenues for improving extraction methodologies.