A simple kinetic model, with only three fitting parameters, for several enzymes production in Petri dishes by solid state fermentation is proposed in this paper, which may be a valuable tool for simulation of this type of processes. Basically, the model is able to predict temporal fungal enzymes production by solid state fermentation on complex substrates, maximum enzyme activity expected and time at which these maximums are reached. In this work several fermentations in solid state were performed in Petri dishes, using four filamentous fungi grown on different agro-industrial residues, measuring xylanase, exopoligalacturonase, cellulose and laccase activities over time. Regression coefficients after fitting experimental data to the proposed model turned out to be quite high in all cases. In fact, these results are very interesting considering on the one hand, the simplicity of the model, and on the other hand, that enzyme activities correspond to different enzymes, produced by different fungi on different substrates.