Fifteen serial Burkholderia cepacia complex isolates recovered over a period of 4 years from a single cystic fibrosis patient were analysed for genomovar status by means of recA sequence determination, and genetic relatedness by RAPD-PCR. Twelve isolates were assigned as Burkholderia vietnamiensis, two as Burkholderia cenocepacia and one as Burkholderia multivorans. B. vietnamiensis persisted in the airways during 4 years, except in three occasions when B. cenocepacia or B. multivorans were isolated. The patient was chronically colonized by B. vietnamiensis with the RAPD-profile 12 and transiently by the RAPD-profile 15.