Atmospheric retrievals from ACE are compared to nearly coincident measurements from HALOE. Comparisons are done for O3, HF, HCl, H2O, CH4, NO, NO2, and temperature. Statistics from 32 profile pairs that were reasonably close in space and time are presented. The temperature retrievals agree to within ¿2 K, an important result as all other retrievals depend on this. ACE gas retrievals are typically higher than HALOE, with the exception of NO and NO2 where HALOE is higher. This comparison helps provide traceability between two important complementary remote sensing missions, lends confidence to the initial ACE dataset, and provides a baseline for future retrieval improvements.