We present a microscopic analysis of current fluctuations in a GaAs n+-n-metal Schottky barrier diode containing electron traps in the active layer. An ensemble Monte Carlo simulation is used for the calculations. We analyze the influence of generation-recombination mechanisms of electrons with traps on the current–voltage characteristics and noise spectra of the diode. The presence of traps reduces both the flatband voltage and the current level in the series-resistance regime. With respect to the noise, significant modifications are observed in the current noise spectra. In the barrier-limited regime, while at low-frequency shot noise is not found to change, the returning-carriers peak is strongly modulated by the influence of the traps. Beyond flatband conditions generation-recombination noise becomes evident at low frequency, exhibiting a quadratic dependence on the current.