The purpose of this study was to examine the effect of gestalt group counseling on the reduction of anxiety and aggressive behaviors of the middle school students. The hypotheses to be tested were as follows : Hi: The students who participate in gestalt group counseling will show less anxiety and aggressive behaviors than the students who do not participate In gestalt group counseling. H2: There will be a significant difference In the reduction of anxiety and aggressive behaviors between the constructed and unconstructed gestalt counseling groups. The participants of the study were 39 second-grade female students sampled from a junior high school located In Suwon city. The participants were randomly assigned, 13 students each, to one of the three experimental conditions: experimental group Ⅰ (constructed gestalt group counseling condition), experimental group Ⅱ (unconstructed gestalt group counseling condition), or control group (no treatment condition). Ninety-minute group counseling session was held once a week for eight weeks by a professional group counselor. Anxiety and aggressive behaviors of the students were measured before and after the experimental treatment. On the basis of the findings of the present study, the following conclusions were made : (1) Gestalt group counseling for the junior high school students is effective on the reduction of their anxiety and aggressive behaviors. (2) There is no significant difference in the reduction of anxiety and aggressive behaviors between the constructed gestalt group counseling and unconstructed gestalt group counseling.