A study was conducted to determine if exogenously applied indole-3-acetic acid would stimulate symmetric or asymmetric compression wood formation in stems of rooted cuttings of Pseudotsuga menziesii (Mirb.) Franco. Dormant two-year-old rooted cuttings were decapitated one cm below the terminal bud and treated with IAA in lanolin emulsion. Plants treated with IAA at 1 or 10 mg/g concentrations produced up to 25 rows of new xylem cells during the three week treatment period, while control plants produced essentially none. Compression wood formation was greater on the upper (originally adaxial) than on the lower side of the stem. The results support the hypothesis that basal curvature of rooted Douglas-fir cuttings is the result of a system developing a transverse gradient in auxin content in the stem leading to asymmetric compression wood formation.