A prospective in-depth follow-up study was made on 146 subjects with whiplash-associated disorders after car impacts. Symptoms indicating temporomandibular disorders (TMD) of minor to moderate grade were noted in three men and three women the first month after the accident, and developed in eight women during the following year. Signs indicating TMD, often asymptomatic, were noted initially in one third of the subjects, more often after rear-end impacts, and associated with increased tension in the masticatory muscles before the accident. TMD were also associated with rostral neck symptoms, headache, and post-traumatic stress, but not with the crash severity, expressed as Δv, below 30 km/h.