Using a reduced intensity stem cell transplantation (RIST) schedule, 24 patients with Ph1 (+) chronic myelogenous leukemia (CML) in first chronic phase were prospectively allografted in 4 Latin American countries: Mexico, Brasil, Colombia, and Venezuela, using HLA-identical siblings as donors. Median age of the patients was 41 years (range 10–71); there were 8 females. Patients received a median of 4.4 × 106/Kg CD34 cells. Median time to achieve above 0.5 × 109/L granulocytes was 12 days, range 0–41, whereas median time to achieve above 20 × 109/L platelets was also 12 days, range 0–45. Twenty two patients are alive 81 to 830 (median 497) days after the RIST. The 830-day probability of survival is 92%, whereas median survival has not been reached, being above 830 days. Eleven patients (46%) developed acute graft-versus-host disease (GVHD), whereas 7 of 23 (30%) developed chronic GVHD. Two patients died 43 and 210 days after the RIST, one as a result of sepsis and the other one of chronic GVHD. The 100-day mortality was 4.4 %, whereas the transplant-related mortality was 8%. RIST for patients with CML in chronic phase seems as an adequate therapeutic option.