An intensity-stabilization system for an argon laser using an electro-optic modulator is described. The authors achieved a degree of stabilization of up to 40 db (factor of 100) for intensity fluctuations below a few kHz. The performance in this frequency range did not reach that expected from the available loop gain. They have identified two serious limiting factors to the performance of their system at low frequency: geometrical fluctuations and frequency fluctuations of the laser light.