The present invention relates to a process for producing a resin particle dispersion, including a step (1) of mixing a polyester resin and a basic aqueous solution to obtain a resin neutralized product; and a step (2) of adding an aqueous medium to the resin neutralized product obtained in the step (1) to emulsify the resin neutralized product, in which a concentration of an ester group in the polyester resin is from 6.3 to 12 mmol/g, a pH of the basic aqueous solution as measured at 25° C. is from 8.5 to 13.5, and a content of an organic solvent in the resin neutralized product is not more than 10% by mass; and a process for producing a toner for development of electrostatic images, including steps of aggregating and coalescing the resin particles in the obtained resin particle dispersion. The present invention provides a process for producing a dispersion of resin particles having a small particle size and a narrow particle size distribution, and a process for producing a toner that has a narrow particle size distribution and is excellent in dot reproducibility and charge stability.