Visceral leishmaniasis, also known as kala azar, is a chronic infectious disease that is caused by parasites of the Leishmania donovani complex. This disease can induce a variety of hematologic symptoms. Visceral leishmaniasis, also known as kala azar, is also known as VL. Fever, an enlarged liver and spleen, weight loss, pancytopenia, and hypergammaglobulinemia are some of the symptoms associated with this condition. The Indian subcontinent is home to this disease in its endemic form, and the states of Bihar and West Bengal are where it is most prevalent. Prior to acquiring the diagnosis of VL, patients with VL may present to the haematologist for a variety of disorders related to their blood or blood cells. The haematological symptom of VL that is seen most frequently is anaemia. Leucopenia, thrombocytopenia, pancytopenia, hemophagocytosis, and disseminated intravascular coagulation are all possible complications of VL. Within a week of starting treatment, patients will see an improvement in their haematological status, and after 4–6 weeks, they will experience a complete haematological response. Relapses are extremely uncommon, and there is no evidence that long-term follow-up results in an increased chance of being diagnosed with hematolymphoid malignancies.