We describe 4 cases of non-Hodkin's lymphomas that were interesting because of their curiosal clinical courses and spontaneous complete remissions during the course of high malignancy lymphoma. We present three of them for the first time in Poland. Case 1: a 61-year old woman was admitted to the hospital because of the headache, lasting for 4 months before hospitalization and right hemiparesis. CT scans revealed the presence of tumor in the temporo-occipital region. The diagnosis of B-cell lymphoma was established at histopathological examination of the postoperative material. Co60--therapy of these region was applied after the operation with good response. Case 2: a 38-year woman was admitted to the hospital because of L5-S1 spondylolisthesis to operate it. During the hospitalization haemolytic anaemia of unknown origin, thrombocytopoenia, splenomegaly, fever and rising acute insufficiency of kidneys, heart, liver and CNS were occurred. The patient died, despite applying corticosteroidotherapy. The diagnosis of intravascular lymphoma was established at postmortem examination. Case 3: a 51-year old woman was admitted to the hospital with diagnosis: anaplastic non-Hodgkin lymphoma B-cell type high malignancy established after the double histopathological examination of lymph nodes and biopsy of the lung. At the admission to the Department of Haematology we stated absolute regression of these changes. The patient had been only observed in the Outpatient Department over 1 year. She died after 6 months since the beginning of the relapse despite intensive chemotherapy. Case 4: a 43-year old man was admitted to the hospital because of great hyperleukocytosis, hepatosplenomegaly and neurological symptoms. The diagnosis: chronic prolymphocytic leukaemia was established. The cerebrospinal fluid examination showed presence of mononuclears which infiltrated CNS. CT scans of the brain revealed leucaemic infiltrations of the hemispheres and cerebellum. The patient died despite intensive therapy due to rising progressive multiorgan failure.