Transformation is one of the cornerstone techniques of molecular biotechnology, and it is an almost obligatory part of any study related to the investigation of gene functions, the production of recombinant proteinsProteinRecombinant protein, or the alterations of the phenotypic features in Komagataella phaffii. One of the most commonly used transformation methods for delivering foreign DNA to K. phaffii cells is electroporation. This chapter provides a simplified and fast protocol for preparing K. phaffii electrocompetent cells and for their transformation by electroporation. In addition, several parameters affecting the transformation efficiency are briefly described.