We conducted a retrospective, nationwide analysis to describe the clinical outcome of adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) undergoing allogeneic hematopoietic stem cell transplantation (HSCT) after being treated with a TKI based therapy. Patients and results: A total of 441 patients were included in the study. The median age at HSCT was 44 (range: 18-70). All 441 patients (100%) received TKI before HSCT (performed between 2005-2016). Of these patients, 404 (92%) were in cytologic complete remission (CR) while 37 (8%) had an active disease at the time of HSCT. Molecularly Measurable Residual Disease (MRD) was negative in 147 patients (36%) at the time of HSCT. The donor was unrelated in 46% of cases. The prevalent source of stem cells was peripheral blood (70%). The conditioning regimen was myeloablative in 82% of cases (TBI-based in 50%) and included ATG in 51% of cases. With a median follow-up after HSCT of 39.4 months (range: 1-145), the probability of Overall Survival (OS) at 1, 2 and 5 years was 69.6%, 61.1%, and 50.3%, respectively, with a median OS of 62 months. Progression Free Survival (PFS) at 1, 2 and 5 years was 60.2%, 52.1% and 43.7%, respectively. OS and PFS were significantly better in patients with CR and MRD-negativity at the time of transplant compared to patients with CR but MRD-positive (50% OS not reached vs. 36 months, P=0,015; 50% PFS not reached vs. 26 months, P=0.003). The cumulative incidence of relapse (CIR) at 5 years was significantly lower in patients with CR and MRD-negativity (19.5% vs. 35.4%, P=0.001). The non relapse mortality (NRM) after 1, 2, and 5 years was 19.1% (95%CI: 15.5-22.9), 20.7% (95%CI: 17-24.7), and 24.1% (95%CI: 20-28.5), respectively. The subgroup of patients with MRD-negative both at HSCT and at 3rd month after HSCT had a better outcome (5 year OS 70%). Conversely, the 37 patients who underwent HSCT with active Ph+ALL had a median OS and PFS of 7 and 5 months, respectively. Conclusions: The median OS of all patients with Ph+ALL, treated with TKI based therapy and allografted in recent years at the GITMO Centers, is 62 months. The outcome of Ph+ALL patients undergoing HSCT after TKI therapy has improved (with a 2 yrs NRM of 20,7%), particularly for younger patients and those achieving a molecular remission before transplant (50% OS and PFS not reached). HSCT remains a standard of care consolidation treatment for Ph+ALL and only prospective randomized trials can suggest a survival benefit of non transplant based treatment strategies.