The measurement of waterborne corticosterone (CORT) concentrations in amphibians is becoming increasingly common. It is promoted as a minimally invasive method of accurately assessing physiological stress with conservation and management implications. It is important that waterborne CORT be explored thoroughly to validate its use as a measure of health, yet many studies complete only a partial validation. In addition, there has been some question as to whether this approach is applicable in terrestrial amphibians. We conducted a multi-pronged validation of waterborne CORT in juvenile Northern Leopard Frogs, which is a common amphibian model in both the laboratory and wild. Our approach included assay validation, injecting animals with adrenocorticotropic hormone (ACTH), using a handling challenge, and analyzing different developmental stages. This presentation will focus on results in juvenile Northern Leopard Frogs, identifying when waterborne CORT levels accurately reflect plasma CORT levels. This study is a valuable contribution to the field as it helps researchers to confidently interpret the meaning of waterborne CORT in a terrestrial-phase amphibian.