Saliva contains cells and compounds, of local and non-local oral origin, namely inorganic, organic non-protein, protein/polypeptide, and lipid molecules. Moreover, some hormones, commonly assayed in plasma, such as steroids, are detectable in oral fluid and peptide/protein, and non-steroid hormones have been investigated. The sports practice environment and athletes' availability, together with hormone molecule characteristics in saliva and physical exercise behavior effects, confirm this body fluid as an alternative to serum. This review focuses on the relation between salivary steroids and psycho-physiological stress and underlines how the measurement of salivary cortisol provides an approach of self-report psychological indicator and anxiety change in relation to exercise performance. The correlation between salivary and plasma steroid hormone (cortisol, testosterone, and dehydroepiandrosterone (DHEA)) levels, observed during exercise, has been considered, underlining how the type, duration, and intensity of the exercise influence the salivary steroid concentrations in the same way as serum-level variations. Training conditions have been considered in relation to the salivary hormonal response. This review focuses on studies related to salivary hormone measurements, mainly steroids, in physical exercise. Saliva use in physical disciplines, as a real alternative to serum, could be a future perspective. © 2010 John Wiley & Sons A/S.