A pesticidal composition in the form of an aqueous emulsion contains: (a) an agriculturally active ingredient in which a retention rate is 50% or more after irradiation with xenon light (290 nm cutoff) at an intensity of 0.68 W/m2 at 340 nm for 8 hours, and a retention rate is 40% or more and 60% or less after irradiation for 56 hours (b) a hydrophobic organic solvent (c) a water-soluble polymer dispersing agent and (d) water wherein 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.