In this chapter we review work on neurotrophic factors for midbrain dopaminergic neurons mainly from the past decade, with a focus on neurotrophins and fibroblast growth factors. We summarize data obtained from animal models of Parkinson's disease, review analyses of neurotrophin, neurotrophin receptor and FGF-2 knockout mice and put these into context with data obtained from patients with Parkinson's disease and from postmortem studies. We provide a brief overview on several other factors (EGF, TGF-alpha, IGF, CNTF, PDGF, interleukins) and their capacity to promote survival and protect lesioned DAergic neurons. TGF-betas are reviewed in a separate chapter (Roussa et al, this volume).