Glucocorticoids have been widely used as a physiological marker of stress, and elevated baseline glucocorticoids levels in vertebrates have been associated with environmental changes. The use of minimally invasive sampling techniques and analysis of non-traditional sample types to monitor stress in wild populations has increased due to the importance of understanding how animals respond to environmental disturbances. The use of saliva samples can be a powerful tool to monitor both endocrine shifts and responses to stressors in wild populations. This sampling method does not require a large amount of manipulation and it can be used to sample smaller species, contributing to an increase of studies in environmental endocrinology and conservation efforts of understudied species. This study validated corticosterone (CORT) measurements in the saliva of the guttural toad (Sclerophrys gutturalis) using samples collected in the field and after a standardized stress protocol. We show that small amounts of saliva (0.018±0.028 g) are sufficient to quantify CORT. Salivary CORT levels were higher after exposure to a standardized stress protocol when compared to field levels of CORT, indicating that saliva samples can reflect biologically meaningful levels of CORT in the guttural toad. Because levels of salivary and plasma CORT were not correlated in either the field sampled animals or following exposure to acute stress, we conclude that CORT in the saliva and plasma might show different response dynamics to stimuli.