To examine whether preimaginal conditioning affect oviposition preference in the diamondback moth, Plutella xylostella, we reared the insects from egg to pupa on an artificial diet and two host plants, the Chinese cabbage (Brassica campestris L. ssp. pekinensis) and common cabbage (Brassica oleracea var. capitata), and then tested the oviposition preference of the ensuing adults between the two host plants. Females reared from the three kinds of food showed similar oviposition preference between the two host plants, and a brief experience of the less preferred host plant common cabbage by the adults increased slightly their preference for this plant. We also reared the insects on an artificial diet with or without addition of a neem-based oviposition repellent and then tested the oviposition preference as affected by the repellent. Larval feeding experience of the repellent did not affect oviposition preference. However, emergence conditioning and early adult learning, affected through a minute amount of repellent carried over from the larval food on pupal cuticle and cocoons, significantly altered oviposition preference. The combined results revealed no evidence of preimaginal conditioning in this insect but strong effect of emergence conditioning and early adult learning.