The Amblyomma cajennense tick species is considered one of the most important and widespread species in Brazil. It salivary secretion has been a target
of several studies in biocenology, as the vector of diseases and in investigations related to antihemostatic properties and
antitumor. To complement this investigation, neutron activation analysis (NAA) was applied to determine concentrations of
elements in saliva samples of this tick species. The saliva samples (50–554 μL) were collected at Butantan Institute (São
Paulo city, Brazil) and they were investigated using the IEA-R1 nuclear reactor at IPEN/CNEN-SP-Brazil. These data were compared
with the values established for Amblyommaamericanum and Amblyomma variegatum species emphasizing agreement only for Cl, K and Na with the A. americanum species, suggesting similarities in the mechanisms that regulate the osmotic pressure in this hematophagous animal. The knowledge
of these limits contributes for tick saliva characterization as well as for the understanding of the many physiological processes,
especially those related to salivary secretion.