Biodiesel fuels have emerged as an important alternative to petroleum diesel for transportation as well as other applications, such as water pumping and irrigation. Biodiesel fuels can play an important role in reducing environmental pollution as well as dependency on fossil fuels. Viscosity is one of the important properties that strongly affects spray characteristics, fuel atomization, and combustion and engine wear. A ViscoScope viscometer was used to measure the viscosities of canola, jatropha and soapnut biodiesel fuels for temperatures up to 523 K and pressures up to 7 MPa. Regression of the data showed that the relationship between viscosity, and temperature followed the modified Andrade equation. (C) 2012 Elsevier Ltd. All rights reserved.