The clinicolaboratory peculiarities of the course of hemorrhagic fever with renal syndrome in 90 males working at oil and chemical plants of Nizhnekamsk depending on age and length of work and in 129 patients never working in this industry are studied. It was found that among the workers of oil and chemical industry the systolic blood pressure was lower the diarrhea was wore opten. Low absolute number of lymphocytes and higher indices of leukocyte index of intoxication, circulating immune complexes and NST-test, lower IgA level in serum in the early reconvalescence period are revealed.