A simple and sensitive extraction-spectrophotometric method for the determination of barium is reported. The 18C6-barium-Rose Bengal (18C6-Ba-RB) ternary complex was quantitatively extracted into dichloromethane, and its absorbance was measured at 565 nm. The calibration graph is linear over a barium concentration range of 0.083 - 4.70 µg ml^-1. The limit of detection of barium was 17.7 ng ml^-1. The relative standard deviation (RSD) of ten replicate measurements was 2.19% for a 0.83 µg ml^-1 barium solution. The interference effects of various cations and anions were also studied and reported. The described method provides a simple and reliable means for determination of trace amounts of barium in real samples.