Performance skills are the actions that are observable elements of an occupation. Occupational therapists analyze how people carry out their activities, often through observation, with the aim of enhancing their participation and satisfaction in life roles. When observing a person doing an occupation, occupational therapists look at performance skills – the smallest observable actions that people do, regardless of age or ability level. This chapter describes three categories of universal performance skills that are the observable elements within most occupations: motor, process, and social interaction. The chapter provides practical examples of observed occupations for each category of universal performance skills. It then explores how the universal performance skills fit into the three-phase occupational therapy process of evaluation, intervention, and outcome evaluation, using an illustrative example. The chapter emphasizes the importance of performance skills in occupation- and person-centered approaches.