Allogeneic hematopoietic cell transplantation (HCT) is potentially curative for acute myeloid leukemia (AML). Impact of lymphocyte recovery on post-transplant outcomes has been suggested but reports are conflicting. We evaluated the impact of lymphocyte recovery at 28 d post-HCT in 191 AML patients using peripheral blood stem cells as graft. Patients were divided into those with absolute lymphocyte count (ALC) ≥ 0.5 × 10(9) /L (n = 111, 58%; high ALC group) and those with ALC < 0.5 × 10(9) /L (n = 80, 42%; low ALC group), at day 28 post-transplant. With a median follow-up of 49 months, overall survival (OS) was significantly improved in the high ALC group (59% at 3 yr) vs. patients with low ALC (40% at 3 yr, P = 0.03). Cumulative incidence of relapse (CIR) was significantly lower in the high ALC group (16% at 3 yr) vs. low ALC group (36% at 3 yr, P = 0.001). Multivariable analysis for CIR demonstrated high ALC group as an independent factor decreasing relapse risk (P = 0.03, HR = 0.49, 95% CI = 0.26-0.92). Multivariable analysis for OS and non-relapse mortality did not demonstrate ALC ≥ 0.5 × 10(9) /L at 28 d post-transplant to be predictive. We conclude that lymphocyte recovery with ALC ≥ 0.5 × 10(9) /L at day 28 post-transplant is associated with less relapse in AML patients undergoing allogeneic peripheral blood HCT, but without survival benefit.