Aim of the present study was to investigate the impact of mental models of attachment and of locus of control on the emergence of both internalizing (anxiety and mood disorders) and externalizing (aggressive behaviors) disorders. They have also been considered differences due to gender and age. Participants were 241 children, 133 males (55.2%) and 108 females (44.8%) aged between 8 and 14 years (M = 9.94, SD = 1.48). Instruments administered were: the Separation Anxiety Test for the measurement of the mental models of attachment, the Nowicki-Strikland Scale for the locus of control, the Self-Report Psychiatric Scales for Children and Adolescents for the psychopathological disorders and the Social Emotional Dimension Scales for the assessment of behavioral patterns. Results highlight association between female gender and internalizing disorders and between male gender and externalizing disorders. As for age, no significant differences between primary and secondary school subjects were found. Multiple linear regression analyzes show a significant effect of insecure attachment and external locus of control on the dimensions of anxiety, depression, obsessive-compulsive symptoms, eating disorders and somatic disorders. Aggressive behavior, on the other hand, is more influenced only by insecure attachment. In particular, in the comparison between subjects who have no disorder and those who present internalizing, externalizing or both types of disorder, a preponderance of ambivalent mental models emerges.