Thioureas, often contained within neoprene to provide water resistance, are an important cause of allergic contact dermatitis (ACD) in those who use neoprene products. We wish to present three cases of thiourea-induced ACD from three different orthopaedic supports containing neoprene. The first case was a 67-year-old woman who developed an itchy rash on her heel three weeks after using a neoprene insole for plantar fasciitis. The second case was a 47-year-old man who developed an itchy rash on his wrist after wearing neoprene wrist splints for psoriatic arthropathy. The third case was a 77-year-old woman who experienced a severe erythematous rash with blistering from a neoprene elbow brace she received following a humeral fracture. All patients were patch tested to the British Society of Cutaneous Allergy Standard and rubber series and a cut piece from all the relevant supports. At 96 hours, all patients had a + reaction to mixed dialkylthiourea, diethylthiourea, and the supports’ material. No other positive patch test reactions were identified. As neoprene is fast becoming one of the most popular materials used for orthopaedic supports, awareness of this reaction and close liaison between dermatologists and orthopaedic surgeons are therefore essential to allow for early recognition of this complication.