Background: Studies have shown that peer victimization is associated with psychological maladjustment, and have implicated such maladjustment in disrupted ability to concentrate. Aims: To investigate the levels of, and associations between, physical, verbal, and social exclusion victimization, fear of future victimization, and disrupted classroom concentration. Sample: Participants consisted of 485 pupils aged 10-11 drawn from 11 junior schools in the UK. Method: Peer- and self-nominations of physical, verbal, and social exclusion victimization were collected in individual interviews. Self-reports of other variables were collected either individually or in small groups. Results: A substantial minority of pupils reported high levels of fear of future victimization and disrupted concentration on class work, and girls reported higher levels of fear of future victimization than boys. All three types of self-reported victimization, all three types of peer-reported victimization, and fear of all three types of future victimization predicted disrupted concentration on class work. Fear of future social exclusion moderated the association between peer-reported social exclusion and disrupted concentration on class work. Conclusions: In addition to tackling victimization "per se," allaying pupils' fears of it happening to them in the future is called for in order to address a hitherto largely overlooked correlate, and possible source, of disrupted classroom concentration.