This study assessed the therapeutic efficacy of thrombopoietin (TPO) in the mouse model of ALS using two treatment paradigms. TPO was administered either daily or in 13-day treatment cycles to SOD1-G93A mice. Quantitative analysis of platelet levels, VEGF and TGF-beta1 trophic factors were assessed. The effect of TPO on disease progression was analyzed by behavioral analysis and clinical examination. TPO treatment increased levels of platelets and TGF-beta1 but not VEGF. This treatment did not affect onset or survival in these mice. Although biologically active, demonstrated by increased platelet and TGF-beta1 levels, rmTPO did not attenuate disease progression in ALS mice.