Jojoba oil biofuel is a potential alternative to diesel fuel with attractive properties, but its flow behavior under the operating conditions of a diesel engine still needs to be clarified. In this study, the rheological properties of the jojoba biofuel are presented in assessment with diesel fuel to experimentally evaluate both their flow behaviors at different operating temperatures. A Fann-type coaxial cylinder viscometer was employed. The shear stress of the tested biofuel rises considerably with the shear rate in a marginally nonlinear manner on a logarithmic scale. Rheograms indicate that the flow behavior decreases gradually and considerably in the temperature range of 30–90 °C. The viscosity of the jojoba oil biofuel declines considerably with the decreasing applied shear rate and temperature. Based on the experimental results, a suitable model is developed for predicting the viscosity characteristics of the tested biofuel during the heating and cooling cycles of a diesel engine.