Low back pain is a common cause of inability to work. At the Rehabilitation Centre of the Uppsala County Council an annual number of more than 100 patients with this condition undergo an investigation aimed at evaluating their capacity for work and their need for rehabilitation. By compiling and analysing the information recorded in the case journals of the patients with low back disorders during the years 1969 to 1971, it was hoped that more knowledge would be gained about the factors constituting a hindrance to rehabilitation. The present paper is a preliminary report on an analysis of 47 case journals unsystematically selected from the entire material. The study verifies a number of previously reported observations, e.g. the low frequency of roentgenological changes. It is also noted that in a remarkably large number of patients no or only slight abnormalities were found on physical examination. Compared with the results of other investigations, there was a very low frequency of concurrent psychiatric disorders and abuse of alcohol. It was considered from this analysis that the information in the case journal material in question is adequate for elucidating the relevant problems in the planned larger investigation; further, it provides motivation for a future follow-up study.