Full skeletal survey was performed on 193 consecutive children presenting over a 6-year period with acute lymphoblastic leukaemia (ALL). A record was made of the degree of bone pain in these patients and 60 others presenting immediately prior to the availability of skeletal surveys. Bone pain was present in 76 out of 253 patients (30%) and radiological bone changes characteristic of leukaemia in 125 out of 193 (65%). A significant correlation was found between the severity of bone pain and the number of bones involved on X ray (r = 0.25, P = less than 0.001), but not between initial white cell counts and bone score (r = -0.14, P = 0.08). There was no significant correlation between the degree of bone pain and survival or length of first remission (P = 0.29 and 0.86). Similarly, the extent of radiological bone disease was of no prognostic significance with relation to survival (P = 0.41) or length of first remission (P = 0.21).