A film technique was developed to obtain children's self-estimates of selected aspects of their own body dimensions under static and dynamic conditions. Subjects were 40 children, ranging in age from 6.10 to 10.10 yr. They estimated their own heights and shoulder widths while viewing projected images of themselves in two conditions, static and dynamic. The condition films displayed the projected image of the subject from 6 in. below to 6 in. above his or her actual height. The subject responded by stopping a remote-controlled projector when the projected image was perceived by the subject to be his or her own body dimension. A nested factorial design was utilized to determine significant main effects of age, sex, condition, and mode (direction of trials). A paired difference test indicated whether the subjects' estimates were in fact significantly different from the actual body dimensions. Analysis showed no significant differences in main effects of age or sex. Self-estimates of selected body dimensions were significantly different from actual, measured, body dimensions. The motion-picture technique was considered successful in obviating several difficulties encountered in the past by workers using other techniques and was effective in introducing dynamics as a condition under which subjects could make self-estimates of their own body dimensions.