Under water-limited conditions, increasing water use efficiency (WUE) is essential for successful crop production. A 7-yr study, to evaluate tillage and tillage timing effects on soil water storage, crop water use, and grain yield of winter wheat (Triticum aestivum L.) and green (spring) pea (Pisum sativum L.) in rotation, was conducted near Pendleton, OR. Tillage treatments included (1) fall moldboard plow after wheat and after peas (control)(FP), (2) maximum tillage (MT)-fall roto-till after wheat and fall sweep after peas, (3) spring moldboard plow after wheat and fall moldboard plow after peas (SP), and (4) minimum tillage (MT)- no-till (NT) after wheat and fall sweep after peas. Wheat and pea yields under MT, FP, and SP were not different. Lowest yields were obtained under MinT during both wheat and pea phases. During the wheat phase, MinT stored the least water (120 mm) due to low surface residues and had the lowest WUE (12.6 kg ha-1 mm-1). During the pea phase, most water was stored under SP (194 mm) and MinT (192 mm) treatments with standing wheat stubble during the winter months but this increased yield only in 1977, the driest year. However, WUE was lowest (12.2 kg ha-1 mm-1) under MinT because yields were hampered mostly by weeds. Given the relatively small yield differences among treatments, the choice of tillage should depend on factors other than water storage and its effect on yield. Improving weed control, retaining stubble for soil erosion control, and reducing sweep operations in MinT, should make it competitive.