The Biomass Fast Pyrolysis Oil Round Robin Test (RRT) was a research work aimed at assessing the applicability of several petroleum related test methods to Fast Pyrolysis Bio-Oils (FPBO). The work was carried out under a Mandate given to CEN by the European Commission (M/525). The Netherlands Standardization Institute, NEN, executed the work for CEN, and coordinated the preparations with CEN/TC 19/WG 41 “Pyrolysis oil”. To achieve this goal, 15 institutions from six different countries have been engaged in the characterization of FPBOs according to ASTM, DIN, EN and ISO test methods. Participants designated for production have been provided with the same FPBO samples for laboratory analysis. Results have been finally collected and compared to provide insights on differences between test methods and replicability of analytical results. A clear outcome of the RRT was that the FPBO product can’t be analysed with the assessed test methods without modifications, and the reproducibility limits set forth by EN ISO 4259 can be hardly achieved.