Described herein are the experimental design and the results of an interlaboratory study of an analytical method to detect haloethers in water. The method, EPA Method 611 - Haloethers, consisted of a liquid/liquid extraction using methylene chloride, an evaporation step using Kuderna-Danish (K-D) evaporators, a cleanup procedure using Florisil sorbent, another K-D evaporation of the fraction from the Florisil column, and subsequent analysis by gas chromatography using a halide-specific detector. The six concentration (three Youden pairs) of spiking solutions used in this study contained bis(2-chloroisopropyl) ether, bis(2-chloroethyl) ether, bis(2-chloroethyoxy) methane, 4-chlorophenyl phenyl ether, and 4-bromophenyl phenyl ether. Six water types were used in the study: distilled, tap, surface, and three different industrial wastewaters. Statistical analysis and conclusions in this report are based on analytical data obtained by 20 collaborating laboratories.