Chlorhexidine gluconate is a chemical antiseptic that is effective against Gram positive and negative bacteria and on certain viruses and fungi. A bacteriocidal and bacteriostatic agent, this cationic drug is absorbed on to negatively charged cell surfaces of organisms, disrupting the cell membrane, which results in increased permeability. Its use is mainly topical as a surgical hand antisepsis, site preparation/cleansing and for pre-genitourinary procedures such as urethral catheterisation. Like any drug, caution should be employed with its use as hypersensitivity reactions are being documented increasingly in the medical literature. In the following case, we present a patient who was catheterised with the chlorhexidine containing Instillagel® (CliniMed, High Wycombe, UK), prior to undergoing elective orthopaedic surgery.