Between January 1989 and July 1995 the search for an unrelated donor (UD) was started for 379 consecutive Italian patients with Philadelphia positive (Ph+) chronic myelogenous leukaemia (CML). 89 (23%) were transplanted. The overall probability of transplant before and after December 1991 was 16% and 49%, respectively (P = 0.0001), and average interval between search activation and graft was 23 months and 13 months, respectively (P = 0.0001). Disease‐free survival (DFS) following 60 consecutive transplants performed before February 1996 was 41.5% at 48 months and was 64% for patients grafted after January 1993. In univariate analysis, five variables had a favourable effect on DFS: year of bone marrow transplantation (BMT) after 1993 (P = 0.0002), HLA‐DRB1 donor/recipient (D/R) match (P = 0.0006), total body irradiation (TBI) containing regimen (P = 0.0006), graft‐versus‐host disease (GvHD) prophylaxis including ‘early’ cyclosporin before the transplant, and a marrow cell dose > 3 × 108/kg of recipient body weight (P = 0.04). Multivariate analysis confirmed that HLA identity (P = 0.006), TBI‐containing regimen (P = 0.0001) and ‘early cyclosporin’ (P = 0.04) were associated with higher DFS. Transplant‐related mortality (TRM) was 67% in patients grafted before January 1993 and 30% in patients grafted subsequently (P = 0.002). Multivariate analysis confirmed DRB1 identity (P = 0.03) and TBI‐containing regimen (P = 0.0005) to be independent factors predictive of low TRM. This suggests that the outcome of patients transplanted from an HLA DRB1 matched donor, after a TBI‐containing preparative regimen, is similar to results recently reported in patients transplanted from geno‐identical siblings. These results indicate that the search should be initiated at diagnosis for patients < 45 years of age and UD BMT should be considered early in the disease course for those with an available DRB1‐matched unrelated donor.