A computer model has been developed to predict diesel engine particulate emission during transients in speed and torque. The computer model consists of a quasi-steady-state engine combustion model, a dynamic engine model, and a dynamic turbocharger model. The model predictions were compared to experimentally measured particulate emissions. Particulate matter was measured under steady-state conditions, over an EPA transcient cycle, and for discrete segments of various transient cycles;The computer model accurately predicts engine air flow rate, turbocharger speed, and instantaneous engine equivalence ratio. The fuel consumption given by the model is within 3% of the experimental measurement over the transient cycle. The brake specific particulate emission during the transient cycle is also accurately predicted by the model. The predicted particulate emission is within 5% of the averaged experimental data over the EPA transient cycle.