Many saprophytic bacteria have LuxR-I-type acyl-homoserine lactone (AHL) quorum-sensing systems that may be important for competing with other bacteria in complex soil communities. LuxR AHL receptors specifically interact with cognate AHLs to cause changes in expression of target genes. Some LuxR-type AHL receptors have relaxed specificity and are responsive to non-cognate AHLs. These promiscuous receptors might be used to sense and respond to AHLs produced by other bacteria by eavesdropping. We are interested in understanding the role of eavesdropping during interspecies competition. The soil saprophyteChromobacterium subtsugaehas a single AHL circuit, CviR-I, which produces and responds toN-hexanoyl-HSL (C6-HSL). The AHL receptor CviR can respond to a variety of AHLs in addition to C6-HSL. In prior studies we have utilized a coculture model withC. subtsugaeand another soil saprophyte,Burkholderia thailandensis. Using this model, we previously showed that promiscuous activation of CviR byB. thailandensisAHLs provides a competitive advantage toC. subtsugae. Here, we show thatB. thailandensisAHLs activate transcription of dozens of genes inC. subtsugae,including thehcnABCgenes coding for production of hydrogen cyanide. We show that hydrogen cyanide production is population density-dependent and demonstrate that the cross-induction of hydrogen cyanide byB. thailandensisAHLs provides a competitive advantage toC. subtsugae. Our results provide new information onC. subtsugaequorum sensing and are the basis for future studies aimed at understanding the role of eavesdropping in interspecies competition.