Two studies examined daily incidents of peer harassment in urban middle schools. Sixth-grade students (M age=11 years) described their daily personal experiences and witnessed accounts of peer harassment, and rated their negative feelings across a 2-week period. In Study 1 (n=95), within-subject analyses across 4 days revealed that both personally experienced and witnessed harassment were associated with increases in daily anxiety, whereas witnessing harassment buffered students against increases in humiliation on days when they personally experienced harassment. Evidence for witnessing as a buffer against increases in humiliation and anger was also found in Study 2 (n=97) that included 5 daily reports. Witnessing harassment also protected students against increases in negative self-perceptions.