Participation of α-synuclein (ASN) in the pathogenesis of Parkinson's disease is undeniable. This protein is important for functioning of neurons. Conformational changes in ASN and its aggregation result in neurodegeneration. Therefore, the factors preventing aggregation and removing the existing deposits need to be identified. The search for the potential agents preventing fibrillation of proteins in neurodegenerative diseases has involved also dendrimers. Dendrimers are relatively new organic polymers topologically based on the structure of the trees. They possess many functional end groups, which are responsible for high solubility and reactivity, and have empty internal cavities. These properties make them suitable for targeting, microarray systems, catalysis or drug delivery systems, carriers of genetic material or contrast agents in clinical imaging. The aim of this study was to examine the role of carbosilane dendrimers in α-synuclein fibrillation process and to assess the structural changes in α-synuclein under the influence of dendrimers. ASN interactions with carbosilane dendrimers were examined by measuring the zeta potential that allowed to determine the number of dendrimer molecules bound to the ASN molecule. The fibrillation kinetics and the structural changes were examined using ThT fluorescence and CD spectroscopy. The results obtained in this study suggest that carbosilane dendrimers can be potential inhibitors of ASN fibril formation. The fact that dendrimers prevent ASN fibrillation in suspension is therefore important for further research because it may lead to the design of effective pharmacological strategies. The work was supported by the grant UMO-2012/04/M/NZ1/00059