Background/Objectives: Pupil size and reactivity have been studied in adult and pediatric populations to objectively measure pain which showed that pupillometry is a promising biomarker for pain measurement. Vaso-occlusive crisis, is a common complication of sickle cell disease (SCD) and better assessment tools are needed. The objective of this study is to establish normative values for pupil size and reactivity in pediatric patients with SCD with the hope that pupillometry can be used as a tool to objectively measure pain and response to treatment. Design/Methods: Institutional review board (IRB) approved prospective study enrolled 82 patients with SCD. Readings were performed using a NeurOptics PLR-2000 pupillometer. The following measures were collected: resting pupil size, % change in pupil size, pupil constriction velocity, and pupil dilation velocity. Results: Forty-four males and 38 females, all black, were studied. Median age was 11 years (range:2-21). The mean minimum and maximum pupil sizes were 3.52mm and 5.08mm, respectively. The mean dilation velocity and maximum constriction velocity were 1.03mm/s and -4.48mm/s, respectively. When comparing our participants with white participants in a previously published pediatric study, there was a significant difference in maximum constriction velocity, maximum pupil size, and minimum pupil size.1 There was no significant difference when comparing means for these parameters. Conclusion: There was no significant difference in pupil size and reactivity between patients with SCD and black patients without the disease. Further investigation of pupillometry within the black population during vaso-occlusive crisis and in the “well state” is warranted in pediatric patients with SCD.