Many amphibian populations have declined and others are at risk. Developmental stability analysis (DSA) has been proposed as an “early warning system” because it may detect environmental or genetic stress before they lead to population declines. Deviations from perfect symmetry (fluctuating asymmetry or FA) may indicate stress. We experimentally evaluated the efficacy of DSA to detect sublethal acid stress in the salamander Ambystoma maculatum. Our results indicate that traditional fitness correlates, such as size at metamorphosis, were affected by pH stress and revealed pond-specific responses to pH treatments. Fluctuating asymmetry was not correlated with pH stress, suggesting that pH stress did not disrupt aspects of the developmental program that enforce symmetry. Furthermore, FA was altered through preservation, changed through time, and differed in fore and hind limbs. Conclusions about developmental stability depended on whether traits were analyzed separately or with a composite index. Finally, we found that measurement error frequently differed among treatments, such as among pH treatments and between live and preserved groups. In such cases, measurement error must be partitioned out of each FA mean square term in order to make valid comparisons. Any amphibian monitoring program should incorporate a variety of techniques appropriate to the species being investigated and should consider including measures of traditional fitness correlates, which may provide more sensitive indicators of changing levels of environmental stress than does DSA.