This article describes the results of a survey conducted in 2003 on methods used by different member countries within the Organization for Economic Cooperation and Development (OECD) to evaluate persistent and bioaccumulative pesticides. The objectives were to establish the differences in taking persistence (P) and bioaccumulation (B) into account in the decision-making process and to establish the influence of the assessors' subjectivity to data interpretation and data selection. Fifteen countries participated in the survey, which generated a vast amount of information on decision making, risk assessment, risk classification, and data treatment. Survey results indicated clear differences in approaches to the use of P, B, and toxicity (T) information in scientific risk assessment. Using the same data for 2 different pesticides, several OECD member countries responded differently in classifying both substances as P, B, and T. Differences in regulatory decision-making were also apparent because, based on identical classifications, several OECD member countries adopted different decisions on pesticide registration; recommendations were based, with respect to technical guidance, on data handling, training of assessors, and handling of uncertainty in risk assessment.