PHODA is an electronic measure that individualizes and guides treatment for individuals with chronic pain. Implicit in its design is recognition that pain-related fear is a driving force that impedes treatment progress. With this tool, patients visually rate their expectations about the harmful consequences of specific movements. This study aimed to (1) develop and validate PHODA-Youth English (PHODA-YE) and (2) evaluate the potential impact of PHODA-YE assessment on treatment outcomes. Participants were 195 youth, age 8 to 20 years, who presented to an outpatient pain clinic for evaluation (n = 99), or enrolled at the Pediatric Pain Rehabilitation Center (PPRC) intensive program (PPRC; n = 96). All patients completed the PHODA-YE along with measures of emotional functioning and disability. Patients in the PPRC completed the measure at both admission and discharge. After eliminating infrequently endorsed and poorly loading items, factor analytic procedures yielded a 4-subscale, 50-item measure with strong internal consistency (from 0.92 to 0.97 across subscales). Fear, avoidance, and functional disability were strongly associated with PHODA-YE scores, supporting construct validity. Within the PPRC sample, PHODA-YE was sensitive to changes over time in relation to functional improvements. Across the PPRC sample, patients found it helpful to complete the PHODA and target feared activities. Altogether, the PHODA-YE is a valid and concrete assessment tool that rapidly identifies specific activities and movements that elicit fearful responses from patients.