Opioid-manufacturing facility workers are at risk of developing occupational contact dermatitis.To describe the causes of occupational allergic contact dermatitis caused by opioids in an opioid-manufacturing facility.A retrospective review was performed of patients assessed at the Occupational Dermatology Clinic in Melbourne, Australia from 2004 to 2017.Fifteen workers from an opioid-manufacturing facility were assessed in our clinic over a period of 14 years. Of these, 11 individuals were diagnosed with occupational allergic contact dermatitis caused by opioids, with seven reacting to thebaine, five to morphine, four to norhydroxymorphinone, two to codeine, and two to oripavine. Two people were suspected of having immediate hypersensitivity reactions to opioids, including one who also had allergic contact dermatitis. Two patients were diagnosed with urticaria, aggravated at work. One patient was diagnosed with a non-occupational rash.We report a case series of workers with allergic contact dermatitis caused by opioids in a manufacturing facility. With greater awareness, including implementation of an educational programme and improved skin protection, the number of cases declined over time. Interestingly, norhydroxymorphinone had not been reported as an allergen before. Further testing is required to establish optimal patch test concentrations of all opiates.