Abstract: There is provided a microbecidal or microbiostatic water-dispersible synergistic combination of a non-ionic surface-active agent that is a mono-ester of a twelve carbon atom aliphatic acid and a polyol and at least one microbecide, e.g., a phenolic compound (including resorcinol compounds). Preferably, the weight ratios of the microbecide-to-ester are between 1:1 to 1:100. These compositions may be dispersed in water and avoid inactivation of the microbecide. Further, the present composition provides activity greater than either the ester or the microbecide alone.