Natural competence for genetic transformation, i.e. the ability to take up DNA and stably integrate it in the genome, has so far only been observed in the bacterial kingdom (both in Gram-negative and Gram-positive species) and may contribute to survival under adverse growth conditions. Bacillus subtilis, the model organism for the Bacillus genus, possesses a well-characterized competence machinery. Phylogenetic analysis of several genome sequences of different Bacillus species reveals the presence of many, but not all genes potentially involved in competence and its regulation. The recent demonstration of functional DNA uptake by B. cereus supports the significance of our genome analyses and shows that the ability for functional DNA uptake might be widespread among Bacilli.