Deep masticator space infections are difficult to manage because of complex anatomy, rapid spread, necrotic tissue and limited antibiotic penetration. We describe the use of biodegradable antibiotic-loaded calcium sulphate beads in a refractory paediatric infection. A 5-year old child developed left masticator and temporal space infection with severe trismus following temporomandibular joint ankylosis surgery at an elsewhere centre. Swab culture isolated Staphylococcus pseudintermedius susceptible to vancomycin and gentamicin. After failure of systemic antibiotics, surgical debridement was performed and antibiotic-loaded calcium sulphate beads were placed for local drug delivery and dead-space management. No external drain was used. At 6 months, mouth opening improved from 9 mm to 25 mm, MRI showed resolution of infection and no recurrence or adverse reactions were observed. This technique appears feasible as an adjunct in selected refractory paediatric masticator space infections.