Hemoglobin Lepore Boston is characterized by abnormal non-α-chains that are the product of a fusion δβ gene originated from an unequal crossing over between misaligned δ and β genes. The investigation of the restriction fragment length polymorphisms (RFLP) of the β-globin gene cluster in 18 Italian Lepore Boston chromosomes indicates that the hybrid gene is linked to two RFLP patterns. The majority of chromosomes show a pattern which corresponds to haplotype V and a minority to haplotype I according to Orkin’s classification. A single Hb Lepore Boston homozygote was homozygous for haplotype V. The two haplotypes differ only for a single site 3´ to the β cluster. Our data allow the speculation that in Italy the Lepore Boston gene might be the result of multiple recombination events.