This study assessed the relationship of length of disability on the rehabilitation outcomes (psychological, sociodemographic and physical elements) of chronic spinal disorder patients in a functional restoration program. Results indicated that two "length of disability" groups, frequently assumed to be distinct in rehabilitation medicine, are in fact strikingly similar in most ways. Although patients with a greater degree of chronicity had slightly worse socioeconomic outcomes on some measures, they were overwhelmingly successful in terms of rehabilitation outcomes typically quoted in the literature for this population. Several demographic variables were found to vary between groups. However, when statistically controlled for, they did not affect socioeconomic, physical or psychological outcomes. Of all the variables studied, only pre-treatment surgery appeared to have predictive value with respect to group membership, again indicating that the groups are more similar than dissimilar across many domains. Thus, in almost all areas assessed, groups showed little or no difference at the two stages of chronicity evaluated in this study, contradicting the prevailing opinion that as the length of disability progresses, there are significant changes which occur that are likely to affect rehabilitation outcomes.