The purpose of this study was to determine the effects of foot orthoses on the pattern of center of pressure in women with forefoot deformities during walking. Nine subjects with a forefoot varus and nine subjects with a forefoot valgus walked across a force platform three times for each of the following five treatment conditions: 1) barefoot, 2) shoes only, 3) rigid orthoses with shoes, 4) semi-rigid orthoses with shoes, and 5) soft orthoses with shoes. Force data were analyzed to determine the area under the center-of-pressure curve. A significant omnibus F ratio was obtained for treatments (p less than .001) and the deformity X treatments interaction (p less than .05) using a two-factor, mixed analysis of variance for repeated measures. Tukey's post hoc comparisons for the Varus Group resulted in significant differences (p less than .05) between the following treatment conditions: 1) barefoot and shoes only, 2) barefoot and rigid orthoses with shoes, 3) barefoot and semi-rigid orthoses with shoes, and 4) barefoot and soft orthoses with shoes. Tukey's post hoc comparisons for the Valgus Group resulted in significant differences (p less than .05) between the following treatment conditions: 1) barefoot and rigid orthoses with shoes, 2) barefoot and semi-rigid orthoses with shoes, and 3) barefoot and soft orthoses with shoes. The shoes-only treatment condition, in comparison with the barefoot condition, significantly reduced the center-of-pressure area for the Varus Group only.(ABSTRACT TRUNCATED AT 250 WORDS)