The European Smoking Tobacco Association (ESTA) in conjunction with the Joint Research Centre of the European Union (JRC) agreed to a joint experiment to determine the variability of data from routine smoking of fine-cut smoking articles. The study was conducted in four phases, each phase taking approximately six months to complete. Each phase consisted of the analysis of three commercially available brands of fine-cut tobacco. The tobacco and tubes for each phase were distributed to each participating laboratory by the manufacturing company. As a result of the co-operation 19 laboratories began this study by taking part in phase 1. Five of these laboratories are directly responsible for, or contracted to provide, analysis of tobacco products for five national Governments within the European Union. Two laboratories were independent contract laboratories and the remainder were associated with the tobacco industry. As a result of company mergers and takeovers or laboratory closures, the number of laboratories that completed all four phases was reduced to 14. The procedures outlined in method ISO 125592-3 were followed throughout. At each phase, each laboratory was required to make four samples according to the protocol using two papers at each of the two weights specified in the method. One hundred FCSAs of each sample were smoked and analysed for each phase using the smoking machine normally used in that laboratory. Each laboratory analysed the samples for NFDPM and nicotine yield. As not all laboratories were able to analyse carbon monoxide, this was not a requirement of the protocol for the study but those laboratories that were able to do so were invited to submit data. The data was analysed on completion of each phase and in total at the completion of the study. The poster will provide details of the protocol for the study and provide the main data for NFDPM and nicotine with limited data for CO. The conclusions of the study suggest that a higher tolerance will be required for the analysis of FCSAs than for manufactured cigarettes. Nevertheless, the study suggests that the analysis outlined in the ISO/CORESTA method is viable. Proposed values will be presented and discussed.