Repeatedly occurring somatoform complaints often cause disruptions in children’s daily life, both in family and school settings. Associated with these complaints, there is an increased demand for medical help in the affected children. Despite the frequent occurrence of somatoform complaints in childhood, only a small number of studies have focused on this subject, and the development and maintenance of somatoform complaints have not sufficiently explained to date. Previous research suggests that many different factors are involved, including insecure attachment, a lack of emotion regulation (ER) strategies, and psychiatric behavior problems. The aim of this study is to examine possible pathways describing the interplay of aforementioned factors, in order to contribute to a deeper understanding of the underlying mechanisms. A nonexperimental cross-sectional study was conducted. Questionnaires were completed by 221 children (female n = 115; Mage = 9.70 years, SDage = .56) reporting on their attachment and ER strategies, and their parents reported on the behavior problems and somatoform complaints. Path analysis revealed a good model fit (Χ2 = p .798, Χ2/df = .415, NFI = .994, CFI = 1.000, RMSEA = .000). Results revealed that attachment anxiety predicted maladaptive ER strategies, and attachment avoidance predicted emotion control. In turn significant paths were found between ER strategies, behavior problems, and somatoform complaints. This study provides a first insight into the underlying mechanisms describing the occurrence of somatoform complaints. Results revealed two developmental pathways, based on attachment quality and mediated through different emotion regulation strategies.Clinical Trial Registration: The project “Impact factors and conditions of somatoform symptoms in childhood within familial and school contexts” is listed in the German Clinical Trails Register (DRKS-ID: DRKS00012444) and the WHO International Clinical Trials Registry Platform.