It is commonly assumed that there is a direct relationship of alexithymia with internalizing symptoms, such as Somatic Complaints. However, the fact that alexithymia is also strongly related to negative mood states suggests that the frequently found association between alexithymia and internalizing symptoms is actually mediated by mood states. Therefore, the aim of this study was to examine the unique contribution of alexithymia to the prediction of internalizing symptoms (self-reported health complaints and worrying/ruminative thoughts) in a population with children and young adolescents (n = 579, mean age 12 years and 2 months) by testing two models through structural equation modelling. The first model assumed an indirect relationship of alexithymia with internalizing symptoms, via mood. The second model also assumed a direct relationship between alexithymia and internalizing symptoms. The results showed a clear misfit of the first model, but a good fit of the second model. These outcomes suggest that there is a unique contribution of alexithymia to the explanation of internalizing symptoms in children and young adolescents over and above negative mood. © 2009 Elsevier Ltd. All rights reserved.