The picture-hosting service said that it has been forced to close following pressure from Twitter over a trademark application.
In a blog post, the company explained: "A few weeks ago Twitter contacted our legal demanding that we abandon our trademark application or risk losing access to their API.
"This came as a shock to us since Twitpic has been around since early 2008, and our trademark application has been in the USPTO since 2009."
After explaining the history of Twitpic's attempts to obtain a trademark, founder Noah Everett added: "Unfortunately we do not have the resources to fend off a large company like Twitter to maintain our mark which we believe whole heartedly is rightfully ours. Therefore, we have decided to shut down Twitpic."
He then ended the statement with a "personal note", thanking users "for letting us be a part of your life and helping you share your experiences over the past 6 years, it's truly been an honour.
"I have learned so much through running Twitpic over the years. Through the many mistakes I've made and lessons learned, to the bad days and the great days. Thank you again everyone…I will miss and cherish the days of Twitpic we had together."
The service will officially close on September 25, but a photo export feature will be released in the next few days.