The purpose of this study was to develop a profile of the use of McKenzie classifications of diagnosis and treatment, by physiotherapists credentialed in the McKenzie method in New Zealand. This system has been in common use for more than 20 years and the inter-rater reliability of the assessment has been previously established for therapists at this level of training. Prior studies identifying the classification of patients according to syndrome and directional preference have been mainly for the lumbar spine. The 34 participants for this study each assessed and classified 10 consecutive spinal patients during a 10-week period. Of the 340 patients assessed, 19 were excluded. Of those with pain arising from the lumbar spine; 140/187 were classified as reducible derangement syndrome, 11/187 were classified as irreducible derangement, 11/187 as dysfunction syndrome, 1/187 as posture syndrome and 24/187 as 'other'. For treatment in the reducible derangement syndrome; 98/140 were given extension, 8/140 were given flexion and 34/140 were given lateral movements of either side gliding or rotation. Classifications and treatment for the cervical and thoracic spine groups followed similar patterns. These findings add to the external validity of the McKenzie method, and support mechanical evaluation of spinal patients according to directional preference.