A decision-support system for produced water management (DISSPROWM) in offshore operations is being developed. The system determines the risk and hazards to human and marine species from non-carcinogenic and carcinogenic pollutants, including radionuclides present in produced water. The DISSPROWM also evaluates the best available treatment technology for treating the produced water whose properties are in the database. The system consists of a Windows-based Graphical User Interface (GUI) developed with Microsoft Visual Basic, which integrates a SQL Server database, a risk assessment model and a dilution model for produced water contaminants. The database contains most produced water pollutants and their important properties that are required in dispersion and risk assessment modelling. The database also contains current produced water regulations and information on some of the selected existing treatment technologies with typical cost data required in the decision-support system. Keywords: best available treatment technology; decision-support system; oil and gas industries; produced water; produced water database; risk assessment.Reference to this paper should be made as follows: Mohammed, N., Husain, T., Bose, N., Veitch, B. and Hawboldt, K. (0000) 'Decision-support system for risk management of produced water in the offshore petroleum industry', Int.