Soybean [Glycine max (L.) Merr.] production is expanding in the Texas High Plains since it has a slightly lower irrigation requirement than corn (Zea mays L.) and supplies feed for an expanding regional swine industry.  Evapotranspiration of irrigated soybean (Group IV) was measured with large, precise weighing lysimeters in 1995, 2003, and 2004 at Bushland, TX.  In 1995, the cultivar, Pioneer 9461, was grown, and in 2003 and 2004 the cultivar, Pioneer 94B73RR^®, was grown.  In all three growing seasons, two weighing lysimeters were used to measure crop water use.  Mean evapotranspiration (ET) was 801, 771, and 611 mm, respectively.  Mean lysimeter yields were 407.7, 474.3, and 315.2 g m^-2.  The resulting water use efficiencies were 0.509, 0.614, and 0.516 kg m^-3.  Maximum daily ET rates were between 10 and 11 mm d^-1 in each season.  The crop coefficient (K_c) for the ET_r reference (alfalfa base) was nearer a peak K_cb value of 0.75 to 0.85 in 2003 and 2004 and in 1995 was closer in agreement with the peak value of 0.95 for K_cb for beans in Idaho.  The peak K_c in 2003 and 2004 agreed well with the 1.12 peak K_cb for the ET_o reference (grass base) for beans in Davis, CA, but the peak K_c was nearer 1.20 in 1995.