The Wessex Head Injury Matrix (WHIM) is an assessment tool designed for use during and immediately after coma. The aim of this study was (1) to test a French adaptation of the WHIM, (2) to compare the WHIM to the Glasgow Coma Scale (GCS) and its extension, the Glasgow-Liège Coma Scale (GLS), and (3) to confirm the sequence of emergence of behaviours. The three scales were used to assess 23 patients admitted to an intensive care unit with a GCS score equal to or less than 8 for at least 1 hour, longitudinally. Results indicated that the WHIM had good concurrent validity with the GCS and GLS, good inter-rater agreement, and excellent test-retest reliability . The WHIM is more appropriate and sensitive than the GCS and the GLS for the period of emerging from coma and immediately afterwards, whereas the GLS is more appropriate than the WHIM for the deepest phase of coma, as it also assesses brainstem reflexes. Furthermore, analysis of our data confirmed the ordering of the 66 items of the WHIM as a function of sequence of recovery from coma, as suggested by its authors.