The purpose of this report is to provide a combined presentation of the worldwide experience gained on fuel failures in water cooled reactors and to give statistical data on fuel failures for the period 1987 to 1994. It contains detailed descriptions of primary and secondary failure mechanisms which occurred in 'western' type boiling and pressurized water reactors (BWRs and PWRs), Soviet type pressurized light water reactors (WWERs) and Canadian type heavy water reactors (CANDUs). It also includes information on detection, examination and analysis of fuel failures as well as on fuel failure prevention and management in plant operation. Contents: 1. Introduction; 2. Historical remarks on fuel failure and design evolution; 3. World overview on fuel failures in 1987–1994; 4. Detection, examination and analysis of fuel failures; 5. Mechanisms and root causes of fuel failures; 6. Secondary fuel failures; 7. Fuel failure prevention and management in plant operation; Conclusions and recommendations.