Optimal allogeneic bone marrow transplantation (BMT) presupposes the use of a HLA-identical sibling as donor. Unfortunately, only about 30% of patients have an HLA-matched donor, so that the use of alternative donors has been increasingly used. We report an analysis of 13 children transplanted using an HLA-partially matched donor as source of haemopoietic stem cells. They suffered of ALL (3 pts), ANLL (1 pt), SAA (2 pts), Osteopetrosis (1 pt), Wiskott-Aldrich Syndrome (2 pts), Severe Combined Immunodeficiency Disease (2 pts) and Familial Haemophagocitic Lymphohistiocytosis (2 pts). Full engraftment was obtained in all 11 of the patients who survived longer than 14 days and, globally, a moderate incidence of acute GvHD (grade II-IV) was observed in the evaluable patients (3 out of 11 with a percentage of 27%); only a patient of the six survivors more than one hundred days after BMT had severe chronic GvHD (16.6%). Four pts (31%) are actually alive and well (mean follow-up 358 days) with a mean Karnofsky score of 95%. Our data suggest that BMT from HLA-partially matched donors could represent a possible alternative therapeutic strategy in children when a compatible donor is not available. This is especially due to the reduced severity of GvHD in childhood and because of T-cell depleted marrow transplants could obtain more satisfactory results when employed in typical pediatric non-malignant disorders (i.e. immunodeficiencies) rather than in leukemia.