摘要:Background: We aimed to investigate the epidemiological, clinical and paraclinical aspects of Visceral Leishmaniasis in Ardabil Province, from 1986 to 2018. Methods: The disease has been diagnosed by a serological validate test as Direct Agglutination Test, parasitological methods, and clinical manifestations. The data were collected and then analyzed. Results: Overall, 2824 out of 69007cases (4.1%) had anti-Leishmania antibodies at titers≥1:3200. The majority of VL cases belonged to Meshkin-Shahr, and then Germi County. The percentages of both male and female cases were 52.8 % and 46.6%, respectively. Approximately 78.1% of cases were less than 5 yr old. The high incidence rate of the disease was recorded in the years 1987 and 2003. 48.6%, 3.2%, and 1.9% of the patients had low titer (1:3200), high titer (1:102400), and suspicious titer (1:1600), respectively. Out of 1200 bone marrow aspiration, 23% were positive, and 77% were negative. Fever, paleness, and hepatosplenomegaly were the main symptoms in patients. Moreover, abdominal swelling, edema, weight loss, lymphadenopathy and jaundice were some other symptoms in the patients. Among biochemistry factors, the levels of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, triglyceride and cholesterol have been increased. The death rate was estimated to be 2.8%, mainly related to the Ardabil and Germi cases. Conclusion: Kala-Azar is still one of the most important infectious diseases in Ardabil Province, and is responsible for considerable death rate in infants. More attention should be done to parasite control and early diagnosis.