The prognostic impact of the presence of a familial trait was analyzed in 1449 patient with chronic lymphocytic leukemia (CLL). A family history of hematologic malignancy (HM) was identified in 181 cases (12.5%) and recorded more frequently among female than male patients (HM: p < 0.05; CLL: p < 0.05). The relative was affected by CLL in 89 cases (6%). Familial and sporadic cases showed non-statistically different proportions of advanced stages (10.8 vs 7.1%) and patients requiring therapy (55 vs 60%) and a similar survival probability at 10 years (67 vs 66%). These data suggest that in CLL the presence of a familial trait does not imply an adverse prognosis.