The purchase follows the launch of ukfamily.co.uk, Disney's own parenting website, last month.
Raisingkids.co.uk, which was launched in 2001, has more than 140,000 unique monthly visitors and a registered database of more than 100,000 parents.
The site was founded by child psychologist and author Dr Pat Spungin, who will continue to work for the site, alongside editor Catherine Hanly and web producer Michael Howard.
Disney intends to use Raisingkids.co.uk to complement the resources offered at ukfamily.co.uk.
According to Disney, there are an estimated 6.5m families with children under the age of 13 in the UK, while more than 4m UK mothers regularly go online.