Teamwork and good communication are central to the provision of high-quality care. A standardized focus-group protocol was used. Analysis assessed emergent themes of patient safety-related effective and problematic clinician communication. Sixty-three focus groups were conducted with clinicians from five Chicago Pediatric Patient Safety Consortium hospitals. Effective and problematic clinician-to-clinician communication themes were described in all focus groups and at each participating hospital. Problematic communication contexts included the communication process for orders, consultations, acuity assessment, management of surgical and medical patients, and the discharge process. Organizational policies and systems leading to patient safety risk included a lack of clear responsibilities and expectations for clinicians and for clinical communication, as well as a lack of a clear chain of responsibility for communication when hierarchical communication barriers affected safe patient care. Results of this investigation highlighted gaps in pediatric clinician communication and opportunities for improvement.