Peripheral blood counts and factors influencing haematological recovery in 98 patients with a relapse-free survival of > or =1 year treated with high-dose chemotherapy (HDC) and peripheral stem-cell transplantation (PSCT) for haematological malignancies were analysed. One year after PSCT full haematological recovery was demonstrated for haemoglobin (Hb) in 47% of patients, for the white blood cell count (WBC) in 94%, and for platelets in 64%; 39% had a trilineage recovery. In the multivariate analysis, recovery was influenced by age (P=0.002), number of reinfused CD34+ cells (P=0.016), Hb at start of HDC (P=0.001), and platelets at start of HDC (P=0.008). One year following PSCT, 61% of patients still have subnormal values in one or more haematopoietic cell lineage, suggesting a limited bone-marrow reserve. Long-term recovery is highly dependent on age, blood counts at start of HDC and number of reinfused CD34+ cells without a threshold, all reflecting the residual function of bone marrow before HDC. Reinfusing more CD34+ cells can accelerate long-term haematological recovery.