Serial pupil examinations remain a mainstay of neurological assessments performed by neuroscience nurses. Integration of pupillometer technology has increased in recent years, because of its ability to address limitations of manual examinations and to evaluate trended data over time. Preliminary research has linked pupillometer values to intracranial pressure (ICP) values, but data on pupillary changes in the setting of increased ICP remain sparse. The purpose of this study was to determine trends in pupillometer values in the setting of increased ICP among critically ill patients with neurological injury. This is a secondary analysis of data where serial pupillometer and ICP readings were recorded hourly on adult patients with neurological injury necessitating critical care management. More than 2100 paired serial pupillometer and ICP readings were obtained from 76 subjects, with a total of 2107 paired readings for the left eye and 2175 for the right eye. There were statistically significant differences in pupillometry values in the setting of increased ICP. Time series analysis indicates that spikes in ICP values resulted in corresponding variations in pupillometer values. Use of automated pupillometry remains a value adjunct to traditional invasive therapies. Evaluation of trended data may provide insight into ICP elevations in the absence of invasive monitoring and warrants additional research.