The relationships between the severity of lameness, the presence of tibial hypochondriac, and the frequency of dust bathing behavior and duration of tonic immobility were studied in 96 broiler chicks kept from day-old in groups of four in wire-floored cages. Dust bathing was observed when the birds were given access for one hour to a tray containing sand or straw. The duration of tonic immobility and the severity of lameness were scored during weeks 3, 4, 5 and 6. After slaughter at 41 or 45 days of age the birds were examined for tibial hypochondriac; 34 birds were classified as having tibial hypochondriac and 54 had detectable lameness problems. Birds with tibial hypochondriac had a higher lameness score, dust bathed on fewer days, and had longer periods of tonic immobility at six weeks than birds which did not have the condition. However, almost all the chicks, including those with tibial hypochondriac dust bathed on day 27 after they had not been given access to the tray for three days, significantly more than on days when they had not been deprived of the tray. Furthermore, lame birds and birds with tibial hypochondriac also dust bathed less with age. Studies of the vertical wing-shaking element of dust bathing confirmed that tibial hypochondriac reduced dust bathing and also showed that during the one-hour tests, sand resulted in more dust bathing than straw.