Delphi is a frequently used research method in the IS field. The last years have seen many variants of the Delphi Method being proposed and used in IS research. However, these variants seem not to be properly derived: while all variants share certain characteristics, their reasoning for differentiation varies inconsistently. It seems that researchers tend to create presumably “new” Delphi Method vari-ants although the underlying modification of the Delphi Method is in fact minor. This leads to a heter-ogeneity of Delphi Method variants and undermines scientific rigor when using Delphi. The study addresses this deficit and (1) identifies variants of Delphi that are differentiated and determines their characteristics, (2) critically reflects to what extent a clear distinction between these variants exists, and (3) develops a taxonomy proposal of Delphi Method variants. The proposed taxonomy helps to clearly differentiate Delphi Method variants and enhances methodological rigor when using the Del-phi Method.