Abstract Objectives To describe the characteristics, treatment and outcome of patients with immune thrombocytopenia with clinical significance (ITPCS) associated with SLE. Methods This retrospective multicentre study included SLE patients who experienced ≥1 ITPCS (defined as ITP with attributable bleeding disorders and/or a platelet count <30×109/l). Other causes of secondary thrombocytopenia were excluded. Major bleeding event (MBG) was defined as Khellaf score >8 and/or WHO score >2. Results A total of 90 patients were included, the median (range) follow-up duration was 80 (6–446) months. ITP was diagnosed before SLE in 25 patients. They presented a high rate of autoimmune haemolytic anaemia (15%), antiphospholipid antibody (62%) and antiphospholipid syndrome (19%). The 25 (28%) patients who experienced MBG had significantly more bleedings at ITP diagnosis and higher bleeding scores, and serositis and thrombosis during follow-up. They required significantly more treatment lines, transfusions and hospitalizations. The 11 (12%) patients who experienced no bleeding event presented a significantly more restricted SLE phenotype (cutaneous and/or articular). Patients received a mean (range) of 4.2 (1–11) treatment lines. Corticosteroids and HCQ allowed ITPCS overall response in one-third of patients. The median relapse-free survival of rituximab (n = 34), AZA (n = 19), MMF (n = 8), thrombopoietin-receptor agonists (n = 16) and splenectomy (n = 19) were 53, 31.5, 61, 24.5 and 78 months, respectively. Four patients experienced thrombotic events after splenectomy and one occurred under thrombopoietin-receptor agonist treatment. Conclusion SLE-ITCS patients displayed a high rate of haematological abnormalities and MBG patients exhibited higher morbidity. Management of thrombocytopenia was highly heterogeneous and many options seem viable.