In this work, a model for predicting evaporation characteristics (constant of evaporation and evaporation time) of cottonseed oil and diesel fuel has been developed and validated experimentally in the temperature range of 684-917 K under atmospheric pressure. The experimental study is based on the fibre-suspended droplet evaporation technique. The theoretical model for predicting evaporation characteristics is based on the determination of transport properties and thermodynamic properties of different phases of cottonseed oil using the properties of its predominant fatty acids (linoleic, oleic and palmitic). Results show that taking into account convection in the quasi-steady model by the correlation of Ranz and Marshall is enough to give a good prediction of the constant of evaporation of diesel fuel in the studied temperature range. For cottonseed oil, the quasi-steady model gives a good prediction for temperatures from 684 K to 773 K while for temperatures from 773 K to 917 K, it is necessary to take into account the convection and the influence of the heating period of the droplet for a good prediction of the constant of evaporation. For the duration of heating and evaporation time, the model gives a rather good prediction for cottonseed oil for the temperature range from 840 K to 917 K. (C) 2012 Elsevier Ltd. All rights reserved.