We have developed two-, three- and four-compartment models of a mammalian olfactory bulb mitral cell as a reduction of a complex 286-compartment model . A minimum of three compartments, representing soma, secondary (basal) dendrites and the glomerular tuft of the primary dendrite, is required to adequately reproduce the behaviour of the full model over a broad range of firing rates. Adding a fourth compartment to represent the shaft of the primary dendrite gives a substantial improvement. The reduced models exhibit behaviours in common with the full model which were not used in fitting the model parameters. The reduced models run 75 or more times faster than the full model, making their use in large, realistic network models of the olfactory bulb practical.