The optimal treatment of patients with breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) that underwent incomplete resection, have advanced stage disease or relapse after resection remains unknown. We describe the treatment and outcome of all 91 Dutch BIA-ALCL patients up to 2023. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Ann Arbor stage I was frequently encountered (74%) compared to stage II (13%) and stage IV (11%). First-line treatment of stage I patients consisted mostly of surgery (88%). Stage II patients were treated with chemotherapy (CT) (67%) or underwent surgery (33%). All stage IV patients received CT. In total, 30% of patients (n = 27) received CT. Relapse frequently occurred (60%) in stage IV disease. The 2-year PFS and OS for stage I, II and IV were 89 and 98%, 83 and 92% and 50 and 90%, respectively. Following second-line treatment, all but one patient remained in remission.