This article presents models to predict mutagenicity, carcinogenicity, developmental toxicity, and skin sensitisation for a set of 27 conazoles. The predictions were performed with the program package CAESAR, which is available on the Internet. The CAESAR programs were developed to support the European Community Regulation on chemicals and their safe use (REACH) and follow the OECD principles for (Q)SAR models used for regulatory purposes. The programs provide a number of information, including a binary classifi cation of a compound as toxic or non-toxic and information on similar compounds from the model’s training sets (similarity sets). In this study we analysed conazole sets using principal component analysis (PCA). The predictions were compared to the currently valid classifi cation of these substances in the European Union (EU) or to the classifi cation proposed at expert meetings of the Pesticide Risk Assessment and Peer Review (PRAPeR) group. The predicted classifi cation for mutagenicity was in good agreement with regulatory classifi cation, the predictions for carcinogenicity and developmental toxicity showed some discrepancy in particular cases, while the predictions for skin sensitisation showed even greater discrepancy.