the condition of having both male and female reproductive organs. Hermaphroditic plants (reproductive system, plant) (most flowering plants) are called monoecious, or bisexual. Hermaphroditic animals, mostly invertebrates (invertebrate) such as worms, bryozoans (moss animals), trematodes (flukes), snails, slugs, and barnacles, are usually parasitic, slow-moving, or permanently attached to another animal or plant.

In human beings, hermaphroditism is an extremely rare sex anomaly in which gonads for both sexes are present, in which external genitalia may show traits of both sexes, and in which the chromosomes show male-female mosaicism (where one individual possesses both the male XY and female XX chromosome pairs). Choice of sex must be made at birth, usually on the basis of the condition of the external genitalia (i.e., which sex organs predominate), after which surgery is performed to remove the gonads of the opposite sex. The remaining genitalia are then reconstructed to resemble those of the chosen sex.

Individuals with the external appearance of one sex but the chromosomal constitution and reproductive organs of the opposite sex are examples of pseudohermaphroditism (q.v.).