Segmented worms, or polychaetes, reproduce sexually or asexually, depending on the individual species. Some segmented worms possess either male or female sexual characteristics, while others are hermaphrodites, which means they possess both.

Most marine worms, earthworms, mollusks and leeches reproduce sexually. The male produces the sperm and the female produces the egg. Some of these segmented worms change sex during their lifetime, however, so a male can become a female and vice versa.

The African leech gives birth to live young, but most segmented worms brood eggs for hatching. The diversity of the reproductive processes is extensive across all varieties of segmented worms, especially among those that reproduce asexually.