A recent report indicated that patterns of systematic variation may be observed in ABR peak latency of children from two age groups, and that comparisons of the children's latency data with similar findings in adults suggest new evidence for developmental changes in the human central auditory nervous system persisting as late as 12 years of age. The current report examines the stability of auditory brainstem response (ABR) peak amplitude for the same three groups of subjects, including: (1) across-age comparisons of absolute amplitude, between-subjects group stability, and within-subjects group stability; (2) documentation of individual differences in amplitude stability by peak and by ear; and (3) demonstration of the degree of replicability of amplitude stability patterns. Results indicate that the same observations are to made for ABR amplitude as for latency; that is, systematic patterns of stability at all three ages, with details that provide additional evidence for developmental changes in brainstem-mediated auditory electrophysiological response continuing into the second decade of life.