Randomly amplified polymorphic DNAs were employed to study the genetic variation and gene introgression in potato dihaploids generated after interspecific pollination of tetraploid cultivars (2n=4X=48, Solanum tuberosum cvs. Irish Cobbler, Superior, and Dejima) by haploid inducer clones (2n=2X=24, Solanum phureja, 1.22, Hes-5 and Hes-6). Genetic variation and DNA marker segregation among dihaploids were observed. Most dihaploids contain tuberosum specific RAPD markers but haploid induer-specific RAPD markers were also found in some dihaploids. Of fourteen different arbitrary 10-mer oligonucleotide primers which showed polymorphism between tetraploid cultivars and haploid inducers used, seven generated amplification products which seemed to be derived from the S. phureja parent. Our results clearly indicate that chromosomes of dihaploids produced by haploid inducers are not pure S. tuberosum and the presence of alien DNA segments would complicate segregation analyses of crosses. However, the introgression of inducer-specific markers into S. tuberosum genome may offer an way to introduce useful traits directly from haploid-inducer into S. tuberosum dihaploid genome.