To provide a method for producing surface-modified metal oxide fine particles, which can produce surface-modified metal oxide fine particles having excellent dispersion stability in dispersion liquids having various compositions; a method for producing improved metal oxide fine particles, suitable as a method for producing metal oxide fine particles to be surface-modified in production of the surface-modified metal oxide fine particles; surface-modified metal oxide fine particles which can be produced by the method for producing surface-modified metal oxide fine particles; and a metal oxide fine particle dispersion liquid including the surface-modified metal oxide fine particles. Surface-modified metal oxide fine particles are produced by a method including coating at least a part of surfaces of metal oxide fine particles with a carboxylic acid compound having a certain structure substituted with an amino group which may be cyclic, and/or carboxylate thereof.