The site carries fundraising hints and tips as well as wallpapers featuring daffodils -- the Marie Curie Cancer Care emblem -- that users can download to their phone.
There are four different wallpaper designs to download. Users will be charged £1.50 to download a wallpaper, but 50p of this fee will be donated to the charity.
The site also has a "one-click" call button for visitors wanting to make donations.
Ashley Schofield, head of customer marketing at Tesco Mobile, said: "We run a mobile internet site for Tesco customers where anyone can read the latest news, sports and gossip as well as download ringtones and mobile games.
"With over 100,000 visitors every week we thought it would be a great place to raise awareness of Marie Curie Cancer Care and generate some extra donations."
Marie Curie Cancer Care, which is Tesco's charity of the year, provides free nursing to terminally ill patients, giving them the choice of dying at home supported by their families.
Throughout 2008, Tesco staff and customers are aiming to raise £2.5m to fund an additional 125,000 hours of nursing care, at home, for terminally ill patients across the UK.
Users can visit the site by texting Marie to 83726. Texts are free to Tesco Mobile and O2 customers. Standard charges apply on other networks.