The paper presents new data on the occurrence of Phacus bętkowskii Stawiński (Euglenophyceae). The species was found in a small midfield pond in southwestern Poland. This is its second locality in the world. The paper includes detailed morphological and metric characteristics of Ph. bętkowskii along with characteristics of its environment, particularly water physicochemistry. Research on a greater number of samples enabled emendation of the species description. Original microphotographs and line drawings of Ph. bętkowskii are presented.