The present study investigated the dimensionality of juvenile delinquents’ perceptions of their school environment, and the relationship between such perceptions and locus of control (LOC). Independent groups of 194 delinquent boys and 314 male junior high school non-delinquents completed 2 questionnaires: a modified Tricket and Moos Classroom Environment Scale for Japanese Students (CES) and the Nowicki-Strickland Locus of Control Scale. Factor analysis of the CES revealed 4 factors: (1) Teacher Control, (2) Sense of Isolation, (3) Rule Strictness, and (4) Digressions in Class. In Study I, there were significant group differences for Teacher Control, Sense of Isolation and Rule Strictness factor scores. Delinquents reported more negative cognition towards teachers, a stronger sense of isolation in class and less of a sense of observing discipline, as well as a more external LOC, compared with non-delinquent pupils. According to the results of Study II, delinquents living in a stable family setting reported less loneliness in the classroom, and the relationship between the delinquent and his father was associated with the youth’s cognition of his teachers. Delinquents with a more internal LOC reported more maladjustment in the classroom, while those with more internal LOC were more favorable toward teachers and peers. In light of these findings, it is possible that delinquents may be restrained from misconduct by improving their relationships with teachers, reducing their isolation from peers, and changing their attitudes toward rules.