Profile and variation of gross motor disability and neural impairments were studied in a series of 30 women, aged 22-44 years, fulfilling the diagnostic criteria for the Rett syndrome (RS). The sequential development of neurological signs and a movement disorder causing immobility in 80% were found. On the basis of acquired and sustained walking ability, the women could be divided into three groups: one comprising those 20% still walking (group III), one those 60% previously walking (group IVA) and the third those 20% who had never developed walking ability (group IVB). Spastic signs, seldom prominent, were found in all the three groups, while dystonic signs were most common in those previously walking, and weakness and wasting in the group that never acquired that skill. Early progressive scoliosis, peroneal weakness and excavated feet, interpreted as lower motor neuron signs mainly due to spinal tract impairment, were most extensive among those never able to walk. Loss of walking was considered a consequence of deranging combinations of weakness and dystonia. The patterns of neuromotor disturbances are discussed in relation to other manifestations of RS.