Study Design. A cross-sectional clinical study. Objectives. To determine whether there are specific symptoms, signs, and functional disability associated with adult spondylolisthesis. Summary of Background Data. In spite of the common occurrence of adult spondylolisthesis, the symptoms, signs, and disability associated with it have not been analyzed in a large, well-defined group of patients. Methods. The symptoms, signs, and disability of 111 consecutive patients with adult spondylolisthesis, before randomized treatment with fusion or physiotherapy, were compared with those of 39 patients with nonspecific low back pain before lumbar fusion. The patients completed a questionnaire covering clinical history and symptoms and submitted a pain drawing. The signs were documented. Functional disability and pain were quantified by 12-function and 2-pain visual analog scales, respectively. Results. Sixty-two percent of the patients reported low back pain as well as sciatica, 7% sciatica only, and 31% low back pain only. Specific signs were infrequent. A positive straight leg raising test result in 12% and an L5 sensory disturbance in 13% were the most common. The symptoms were similar in patients with spondylolisthesis and chronic low back pain, but the chronic low back pain group reported more functional disability. Patients with a nonorganic pain drawing (widespread, nonspecific pain) were more often blue collar workers, were more often and longer on sick leave, and reported reduced mental condition, sexual function, functional ability, and more pain than patients with an organic pain drawing (localized, specific pain). Conclusions. The clinical pattern and functional disability in adult spondylolisthesis and in low back pain of nonspecific origin are similar. Sciatica in adult spondylolisthesis is typically not associated with a positive straight leg raising test result.