Silver halide sols stability has been investigated in terms of anion nature and disperse phase concentration. It is shown that at equal concentration sols stability decreases during the transition from iodide to chloride. Stability decrease results from the increase in particle size of the dispersed phase due to higher solubility of silver chloride and lower adsorptive capacity of chloride ions. The increase of particle size during the transition from silver iodide to silver chloride is confirmed by turbidimetric method, and the decrease of sol particles charge — by finding the coagulation threshold. The increase of silver halide sols sedimentation stability is observed at lower concentration of disperse phase. It has been shown that the exposure of sols to a high-frequency electromagnetic field (studied range of frequencies is from 100 to 200 MHz) increases their stability, as confirmed by turbidimetric measurements. Electromagnetic impact effectiveness depends on the frequency and exposure time. As a result of electromagnetic field exposure autocoagulation processes either significantly slow down or somewhat accelerate depending on the frequency of electromagnetic field. Frequencies corresponding to the maximum change of sols optical properties depend on anion nature.