Madonna's children's book The English Roses has sold more than 500,000 copies worldwide, her US publisher has said.
The book sold 8,000 copies in the UK in its first week
Nicholas Callaway also said he hoped to sign deals to translate the book into 50 languages by the end of this week's Frankfurt Book Fair.
The book sold 8,000 copies on its first week on sale in the UK.
Next month sees the release of Madonna's second children's book, Mr Peabody's Apples - a story about a teacher falsely accused of theft.
Praising the international success of the first book, Mr Callaway said: "We are now at 37 languages. We hope to reach 50 by the end of the fair.
"We have surpassed 500,000 in sales around the world so far. We are on track to reach a million by the end of the year.
"Madonna is using the power of her fame to encourage and inspire children how to live life rightly and thoughtfully."
To mark the launch of The English Roses in September, Madonna threw a tea party in Kensington, west London, inviting friends and celebrities and their children, including actress Patsy Palmer and interior designer Linda Barker.
The guests were invited to walk up a pink, sparkly carpet, surrounded by barriers adorned with butterflies and roses.
Madonna then read an extract of the book - aimed at children over the age of six - to the assembled young audience.
In a review of The English Roses for BBC News Online, children's poet Michael Rosen wrote: "Madonna takes on the voice of a slightly bossy teacher, telling her readers to not interrupt and to listen carefully."