Significant advancements have been made in the development of procedures to systematically identify preferred stimuli that may function as reinforcers for persons with developmental disabilities. Indirect assessment procedures include care provider and client interviews, whereas direct assessment procedures involve systematically exposing participants to stimuli while recording their responses. These types of direct assessment procedures can be categorized as either approach-based or engagement-based. Approach-based procedures involve recording the individuals' approach responses to stimuli presented singly or concurrently with other stimuli, whereas engagement-based procedures involve recording duration of engagement with stimuli. Although the predictive validity of indirect preference assessment procedures has yet to be established, using them in combination with direct measures of preference may be most efficacious for identifying potential reinforcers. Recent research on preference assessment procedures used with persons with developmental disabilities is reviewed and the variables that one might consider prior to selecting which procedure to use in a given situation are discussed.