According to Cloninger’s model, personality is conceptualized in temperament and character traits contributing to a child’s psychosocial development. Additionally, parent–child interaction is important for the child’s socio-emotional development. To date, the relationship between attachment and temperament and character for child mental health development and its effects on parents remains mostly unclear. The aim of the present study was thus to examine the relationship of attachment, temperament and character, parental stress, and mental health problems among 125 children (mean age = 7.14 years) in Switzerland. Temperament and character, attachment disorder (symptoms), parental stress, and mental health problems were assessed with psychometric questionnaires; attachment was assessed with an additional observational measure. Descriptive characters of the sample were presented, and group differences and correlations were computed. For temperament traits, results revealed significant group differences for novelty seeking and persistence and attachment disorder types. For character traits, the findings showed significant group differences for self-directedness and cooperativeness and attachment disorder types. Moderate effect sizes for groups differences were found. Further, the mixed-type (inhibited and disinhibited) and inhibited attachment disorder type were the most burdened groups. The present findings suggest that temperament and character traits, as well as parental stress and mental health problems are associated with the occurrence of attachment disorders among children. Future longitudinal studies with larger samples are needed to examine the causal relationships of temperament and character with attachment, including person-related and environmental factors among children.