Aim: Prosthetic loosening has emerged as a most serious long-term complication after Joint Arthroplasty and the most common cause for revision. Arthroplasty is performed either under a general anaesthesia or a spinal/ epidural or a combination of the two. During general anaesthesia Sevoßurane is used for induction and maintenance. We investigated the effect of Sevoßurane on bone cement in an in vitro setting. Materials & Methods:. 40 beads of roughly the same size were prepared from 2 mixes in a sterile condition in vacuum. 20 of these beads were scanned initially under an electron microscope at 2 levels of magniþcation. The surface images of all the cement beads were analysed. Equal numbers of scanned and unscanned beads were separated into 2 groups of 20 each. They were immersed into 2 jars of normal saline. One was connected to the anaesthetic apparatus and exposed to Sevoßurane at a concentration of 2.5%. The other group (control) was exposed to oxygen. This was performed for 2 hours in an orthopaedic theatre. All the beads were then scanned. Results & Conclusions: The post Sevoßurane exposure images revealed a large number of pits of irregular dimensions on the surface. There were no changes on the surface of control beads. This suggests that in clinical concentrations Sevoßurane can affect the surface of bone cement and its mechanical properties. This can in turn affect the bone cement interface and be a potential cause of prosthetic loosening.