Introduction: the parotid glands play a fundamental role in the synthesis and secretion of proteins such as the zymogens of the salivary amylase responsible for the degradation of starches, an important mechanism in the formation of the alimentary bolus, and other protein molecules that accompany the structuring of the saliva, which perform fundamental functions in digestion. In this context, the aim of the present study was to determine morphometric parameters of serous glandular structures subjected to infrared laser stimulation. For this, twelve-month-old Sprague Dawley rats were divided into four groups of 4 animals each: control group and those stimulated with doses of 4, 8 and 16 J/cm2. Once the rats had been euthanized, the respective parotid glands were extracted and processed for optical microscopy, obtaining micrographs on which morphometric studies were conducted. The results showed that the cellular, acinar and nuclear areas increased significantly in the experimental group irradiated with the 16 J/cm2 dose compared to the control group and the other experimental groups. However, considering the number of zymogen granules, a remarkable reduction in the groups irradiated with 8 and 16 J/cm2 was observed compared to the control group. The granular area was also altered, evidencing a significant reduction in the 4 and 8 J/cm2 experimental groups compared to the control group. By contrast, the 16 J/cm2 group showed an evident increase in area compared to the other experimental groups. It is clearly demonstrated that the inductions of infrared laser compared to the controls revealed noticeable differences in all the components analyzed, which could provide background on different functionalities in the metabolism of these glands.