A growth model for uneven-aged mixed-conifer stands in California was developed with data from 205 permanent plots. The model predicts the number of softwood and hardwood trees in nineteen diameter classes, based on equations for diameter growth rates, mortality and recruitment. The model gave unbiased predictions of the expected number of trees by diameter class and species group over eight to twelve years, on 28 validation plots that were not used in model estimation. The results of predictions of undisturbed growth over more than a century were consistent with previous knowledge about succession and productivity in this forest type. The growth model, embedded in the CalPro simulator, was applied to project the effects of managing stands to maintain the current average stand state over the observed plots, with cutting cycles of ten or twenty years. The results suggested that uneven-aged management could match the productivity of even-aged systems. The ten-year cutting cycle led to higher productivity, higher present value of harvests, higher tree species diversity but lower tree size diversity than the twenty-year cycle.