Objective: To report a case of Chronic Lymphoid Leukemia in a 28-year-old young subject, with variable clinical features and a TP53 mutation, diagnosed and followed up in the Onco-Hematology department of the HNN. Observation: 28-year-old patient, having consulted for polyadenopathy and physical asthenia, whose clinical examination found a conscious patient, submaxillary, laterocervical, axillary and inguinal lymphadenopathy, bilateral, symmetrical, painless and non-compressive whose largest measures 3 cm in diameter. Hepato-splenomegaly and epistaxis. Predominantly lymphocyte hyperleukocytosis, immunophenotyping revealed low CD19+, CD5+, CD23+, CD20 monoclonal B lymphoid proliferation. The Matutes score was 4. A karyotype showed a three-chromosome translocation; the short arm of a chromosome 2, the long arm of a chromosome 11 and the long arm of a chromosome 13, and a translocation between the long arm of a chromosome 6 and the long arm of a chromosome 18. A FISH objectified a led 17p. The diagnosis of Binet Stage C CLL with positive del 17p and complex karyotype was retained. Despite the poor prognosis, the R-C (Rituximab-Chlorambucil) protocol was instituted with once-weekly transfusions. The patient is still alive in partial clinical and biological remission. Conclusion: Despite therapeutic progress, the presence of the deletion of chromosome 17p with TP53 mutation and the young age of the patient does not change the patient's prognosis.