The biotransformation of metals is an exciting, developing strategy to treat metal contamination, especially in environments that are not accessible to other remediation technologies. However, our ability to benefit from these strategies hinges on our ability to monitor these transformations in the environment. This involves monitoring metals in both solid and aqueous samples, distinguishing between different chemical states, and obtaining information on the activities of specific microbial taxa in communities that inhabit the treated site. Accomplishing these goals requires cooperation among scientists from various disciplines and would benefit from both new, innovative approaches and the tailoring of established methods to control metal mobility in the environment.