Background: The aim was to examine the validity of a new measure, Te Waka Kuaka, in assessing the cultural needs of Māori with traumatic brain injury (TBI). Methods: Māori from around Aotearoa, New Zealand were recruited. 319 people with a history of TBI, their whānau (extended family members), friends, work associates, and interested community members participated. All completed the 46-item measure. Rasch analysis of the data was undertaken. Results: All four subscales; Wā (time), Wāhi (place), Tangata (people) and Wairua practices (activities that strengthen spiritual connection) were unidimensional. Ten items were deleted because they did not fit the model, due to statistically significant disordered thresholds, non-uniform differential item functioning (DIF) and local dependence. Five items were re-scored in the fourth subscale resulting in ordered thresholds. Conclusions: Rasch analysis facilitated a robust validation process of Te Waka Kuaka.