The sesquiterpene β-caryophyllene is a ubiquitous component of many plant resins and has been used in the cosmetic industry to provide a woody, spicy aroma. Recent clinical studies have shown its potential effectiveness as an antibiotic, anesthetic, and anti-inflammatory agent. Additionally, there is significant interest in sesquiterpene accumulation in phototrophic microorganisms for the production of biofuels. Currently, the isolation of β-caryophyllene relies on purification methods from oleoresins extracted from large amounts of plant material. The design of a cyanobacterium platform that produces β-caryophyllene may provide a more sustainable and controllable means of production, allowing for an increase in yield without the potential deleterious effects to natural sources. To this end, the β-caryophyllene synthase gene (QHS1 ) from Artemisia annua (Chinese wormwood) was stably inserted via double homologous recombination into the genome of the cyanobacterium Synechocystis sp. strain PCC6803, under the control of the strong endogenous psbAII promoter. Gene insertion into Synechocystis was confirmed through polymerase chain reaction assays and sequencing reactions. Transcription and expression of QHS1 was confirmed using reverse transcription PCR assays and production of β-caryophyllene was confirmed in the transgenic strain using gas chromatography with flame ionization detection and mass-spectrometry detection.