This chapter explores how to conduct a practice evaluation. It begins with a discussion of informal approaches to evaluating one's social work practice followed by a discussion of formal practice evaluation using single-subject design (SSD) methodologies. The chapter reviews components of an SSD evaluation as well as common designs. This is followed by a section on analyzing SSD data, an SSD case example and a discussion of the ethics and social justice issues associated with SSD practice evaluations. The chapter helps the reader to describe two approaches to informal practice evaluation; engage a client in a social work practice evaluation; and identify three common single subject designs. It conducts SSD practice evaluations; creates a line graph with a celeration line. The chapter visually and statistically analyzes SSD data; and identifies ethical issues associated with SSD practice evaluations.