The aggregation of α-synuclein (αSN) into oligomeric structures has received increasing interest during the last 10-15 years. The oligomers' potential involvement in Parkinson's disease makes them a promising therapeutic target. Therefore reproducible protocols to prepare and analyze oligomers are very important to allow direct comparison of results obtained by different research groups. In this chapter we present one established method to obtain αSN oligomers from a monomeric ensemble in a relatively easy manner. Also, we briefly discuss a selection of biophysical methods which allow for a quick characterization of oligomer purity and structure.