• A.J. Jacobs contributed articles based on what he has learned after reading the entire Encyclopedia Britannica, as described in his book The Know-It-All.

• Ken Jennings, of Jeopardy fame, writes a feature each issue called Six Degrees of Ken Jennings, in which he plays the game Six degrees of separation with two people or things that are unrelated except by the way they sound, like Benedict XVI and Benedict Arnold or Isaac Newton and Apple Computer.

• Features: Some examples of featured articles include an expose on Shel Silverstein's darker side and a collection of the 25 Most Important Questions in the Universe.
• right_brain: Contains articles about "right brain" topics, like art and literature. Some examples of right_brain articles have included The Thinker, James Joyce, and Ming vases.
• left_brain: Contains articles about "left brain" topics, like science and logic. Some examples of left_brain articles have included string theory, the Human Genome Project, and black holes.
• scatter_brained: Contains 10 pages of trivia, facts, and anecdotes from all different categories of knowledge.
• spinning the_globe Contains articles about religion, history, and world culture.
• The Quiz Each issue contains a brief quiz in the back of the magazine.

Recurring themes

• Every year, one issue of mental_floss is known as the "Ten Issue". It will usually feature lists of ten things focusing on one subject such as: "Ten Most Forgettable Presidents", or "Ten Famous Monkeys in Science". mental_floss has currently put out nine "ten issues" to date.

• The Quick 10: Brief lists of ten people, locations, events, or products that fit a specific category
• Brain Game: Original logic and math puzzles
• Morning Cup of Links: Interesting links to news stories, videos, and memes from across the internet
• 5 Questions: Daily sets of questions which ask trivia from several different subjects
• Lunchtime Quiz: Daily quizzes which ask trivia questions from one specific subject
• Feel Art Again: Lists of trivia related to an artist or famous work of art
• Dietribes: Lists of trivia about food and nutrition
• The Amazing Fact Generator: A page which generates random facts and trivia

T-shirts

• "Pluto 1930-2006, Revolve in Peace"
• "There's No Right Way to Eat a Rhesus"
• "Simple as 3.141592...
• "When Life Gives You Scurvy, Make Lemonade"
• "Pavlov: The Name That Rings a Bell"

Books

• Mental Floss History of the World: An Irreverent Romp Through Civilization's Best Bits
• Genius Instruction Manual
• Scatterbrained
• What's the Difference?
• Cocktail Party Cheat Sheets
• Condensed Knowledge
• Forbidden Knowledge
• Instant Knowledge
• In the Beginning
• Be Amazing

In A Box Series

• Law School In A Box
• Med School In A Box
• MBA in a Box

Other

• mental_floss board game
• mental_floss water bottle

• Listed as one of the Chicago Tribune's 50 favorite magazines in June, 2007
• Listed as one of PC World's 100 favorite blogs in June, 2007
• Will Pearson and Mangesh Hattikudur among Inc. magazine's 30 "coolest young entrepreneurs