This study investigated the relationship between therapist common factors behaviors and changes in client constructive communication during couple therapy. Research suggests that common factors are associated with client improvement, but research on these factors in couple therapy is lacking. This study was a secondary data analysis of 41 couples presenting with mild to moderate psychological and physical partner aggression who received ten sessions of couple therapy at a university family therapy clinic. The study examined the relationship between therapist collaborative behavior and use of systemically based techniques coded from the fourth couple therapy session, and changes in client constructive communication, measured by client cognitions during conflict, client and partner behavior during conflict, and video coding of couple communication. Minimal significant links were found, but unexpectedly, therapist use of systemic techniques was negatively associated with change in female constructive problem solving cognitions. Implications of these findings are discussed.