Burkholderia cepacia is an environmental bacterium, capable of colonising vegetal and animal tissues, involved in human opportunist nosocomial infections, and above all, in pulmonary colonisations in patients with cystic fibrosis. In these patients, infection may be followed by a severe deterioration with bacteraemia, leading to death. Moreover, owing to the epidemic spread of some clones within cystic fibrosis communities, strict preventive guidelines have to be instituted. Early detection of Burkholderia cepacia colonisation is therefore essential, and requires the use of selective media. Identification by means of conventional procedures may be problematic, all the more as the previously named Burkholderia cepacia strains have been recently shown to constitute five genomovars (I to V), collectively designated the "cepacia complex", of which only three are classified as new species (II = Burkholderia multivorans; IV = Burkholderia stabilis; V = Burkholderia vietnamiensis). Moreover, closely related species, particularly Burkholderia gladioli, are also involved in cystic fibrosis. Many questions still need clarifications, regarding pathogenic mechanisms and propensity for the cystic fibrosis lung of these organisms. Antimicrobial therapeutic options for B. cepacia complex infections are limited by their innate and acquired antibiotic multiresistance.