Incredible Births
- Site designed with emphasis on multiple births, such as twins, triplets, quadruplets, quintuplets.
- http://www.incrediblebirths.com

Facts About Multiples
- Information on twins, triplets, quadruplets, quintuplets and higher order multiples. Features a database of multiple birth families, statistics, basic information on twinning, world records and information on fakers.
- http://www3.telus.net/tyee/multiples/index.html

BellaOnline Twins
- Information on vanishing twins, events, scholarships and twins in school.
- http://twins.bellaonline.com

Twin Connections
- Twin Connections celebrates the unique and mysterious bond between twins by providing a place for twins, and their families and friends, to share and read twin stories and photos, learn interesting twin facts and news and join an online twin community.
- http://www.twinconnections.com

TwinsRealm.com
- Mirror twins from Australia share photos, twin stories, links and information on twin festivals and celebrations.
- http://www.twinsrealm.com/

Twins Network
- A resource for understanding twins and sharing information. Surveys, facts, news, trivia, links.
- http://www.twinsnetwork.com/

The International Twins Association
- A non-profit, family-oriented organization to promote the spiritual, intellectual, and social welfare of twins and multiples throughout the world.
- http://www.intltwins.org/