A retrospective study of pain laterality was performed on a sample of 1006 patients suffering from chronic pain attending the Centre for Pain Relief, Walton Hospital, Liverpool, U.K. 769 patients reported unilateral pain. There was no significant difference in the numbers presenting with right-sided and left-sided pain. When the data for different sites of pain were analysed separately a similar picture emerged. No statistically significant differences in the frequency of left- and right-sided pain were found at any site. Similarly, when the data for different diagnoses were examined, there were no significant differences in the laterality of the pain found in any diagnostic category. This study fails to support the general hypothesis that pain, when lateralised, occurs more frequently on the left.