This chapter discusses the special challenges of evaluating mobile visualizations. Many research goals can be addressed by an evaluation study including validating rapid perception of differences in data or examining the long-term use and impact of visualizations. Different methods, time-scales of research, and participant recruitment strategies are needed depending on the questions that one wants to answer. This chapter explores the literature, discussing a variety of goals and evaluation approaches, highlighting best practices and making recommendations for future approaches to evaluating mobile visualizations.