The performance of two children with traumatic spastic dysarthria, aged 10 and 14 years, on maximum performance tasks was compared with that of two closely matched children with perinatal spastic dysarthria, and reference groups of five children with perinatal spastic dysarthria and five control children with normal speech. Results showed that performance of the perinatal spastic children on all three tasks was poorer than that of their peers with normal speech. In contrast, the traumatic spastic children performed within the normal limits on maximum sound prolongation and fundamental frequency range, but their maximum repetition rate was extremely slow. The overall low performance of the perinatal spastic children could be the result of inadequate motor development in addition to the neurological impairment. The traumatic spastic children--with a normal developmental history--compensated for their impairment by slowing down their speech rate. Therapeutic implications are suggested.