Inflammatory processes and other failures related to the immune system are common features associated with Alzheimer's disease (AD), in both brain and the peripheral system. Thus, the study of the main organs of the immune system may have a great potential for the elucidation of pathological mechanisms underlying these abnormalities. This is the first metabolomic investigation performed in spleen and thymus from transgenic mice of AD. Tissues were fingerprinted using a metabolomic platform comprising GC-MS and ultra-HPLC-MS. Multivariate statistics demonstrated significant differences in numerous metabolites between the APP/PS1 mice and wild-type controls, and it was proven that multiple biochemical pathways are disturbed in these organs including abnormal metabolism of phospholipids, energy deficiencies, altered homeostasis of amino acids, oxidative stress, and others. Therefore, these findings highlight the importance of the proper metabolic functioning of peripheral immune system in the development of neurodegenerative disorders such as AD.