A pesticidal composition is provided in the form of an aqueous emulsion, containing: (a) an agriculturally active ingredient in which a retention rate is less than 50% after irradiation with xenon light (290 nm cutoff) at an intensity of 0.68 W/m2 at 340 nm for 8 hours; (b) a hydrophobic organic solvent; (c) a water-soluble polymer dispersing agent; and (d) water. Liquid droplets in which the agriculturally active ingredient is suspended or dissolved in the hydrophobic organic solvent are emulsified in an aqueous continuous phase. A weight ratio of the agriculturally active ingredient to the hydrophobic organic solvent is from 5:95 to 70:30. With this pesticidal composition, it is possible to inhibit photodegradation of the agriculturally active ingredient.