Density functional theory and molecular orbital theory are used to calculate the fukui function and the condensed fukui function for several enolate ions in order to carry out an analysis of the different effects that have an influence on the chemical reactivity at the carbon and oxygen atoms. It is shown that substituent, substrate, and solvent effects may be explained in a unified way in terms of the values of the condensed fukui function when these are analyzed through a local version of the hard and soft acids and bases principle. The results suggest that it could be interesting to carry out experimental work that may confirm the importance of the hardness and softness parameters to get a better understanding of enolate ion chemistry.