Anti-HVA IgM, HBsAg, anti-HBc IgM, anti-HVC were determined in the blood sera and saliva specimens obtained from patients with acute hepatitis A, B, C (HA, HB, HC) and from healthy persons of the control group. 37 HA patients, 27 HB patients and 24 HC patients, observed in the dynamics of the disease (for a period of 1 month and longer from the appearance of manifestations of the disease), as well as 30 practically healthy persons (the control group) were examined. Anti-HVA IgM could be found in saliva specimens taken from the HA patients 100% of cases, but could not be found in saliva specimens from the persons of the control group and HB patients. The presence of HBsAg was established in 92.8% and anti-HBc IgM, in 100% of cases in saliva specimens from patients with acute HB. In no case HB markers were found in saliva samples obtained from HA patients and from the persons of the control group. In HBsAg-positive saliva specimens HB virus DNA was detected by the method of polymerase chain, reaction, which opened new aspects for the modern interpretation of the role of saliva as a factor in the natural transmission of HB. Anti-HVC could be found in all patients both in the blood serum and saliva specimens, but proved to be absent in the persons of the control group, as well as in HA and HB patients. The dynamic study of HA, HB and HC patients for the detection of anti-HVA and anti-HBc IgM, HBsAg and anti-VHC demonstrated the possibility of detecting these markers for 1 month and longer in the blood sera and in saliva specimens. The results of these investigations suggest that saliva specimens may be regarded as an alternative to blood sera in the diagnosis of HA, HB and HC in patients with acute viral hepatitis; these results also open prospects for the use of saliva specimens as an object of study in diagnostic laboratories, the deciphering of viral hepatitis outbreaks, the diagnosis of HA in persons with anicteric forms of HA.