Tenzer was born in Oakland, California, and grew up in Piedmont, California east of San Francisco. She graduated from the University of California, Berkeley with a B.A. in Communication and Public Policy, and from University of Southern California with an M.A. in Communications Management. She is married and is the mother of three children.

A marketing and advertising executive for many years, Tenzer became frustrated with the divisive political climate in the U.S. surrounding the 2004 elections. One day after having lunch with friends who were bemoaning the sad state of the world, an idea occurred to her: Instead of worrying about the big problems she could not solve, she would look for small problems that she could solve.

She committed to doing one nice thing for someone every Monday, her hardest day of the week. After hearing about it, her friends urged to start a website, which she did - www.DoOneNiceThing.com, and word of it spread rapidly. The movement has members in ninety countries.

Tenzer posts a different “nice thing” to do each week as well as stories about the kind people who do them. Do One Nice Thing members have:

mailed more than 75 tons of school supplies to U.S. soldiers in Afghanistan and Iraq, who give them to local children so they can studysent tens of thousands of cans of food, packages of pasta and boxes of energy bars to food banks and needy schoolsgiven numerous backpacks to foster children who often carry the little they own from home to home in garbage bagsdonated thousands of blankets to U.S. soldiers in Iraq who give them to local people living without electricity or heatand sent countless books to schools, libraries and hospitals

Tenzer is the author of Do One Nice Thing: Little Things You Can Do to Make the World a Lot Nicer, released by Crown Publishers (Random House) on May 5, 2009.ISBN 978-0-307-45421-8 (0-307-45421-5)[1]It is a book for people who want to do good but can’t find time to do it. Do One Nice Thing offers readers over 100 ideas for easy, inexpensive ideas to help kids, friends, co-workers, soldiers, the planet and more.

From Publishers Weekly: “Tenzer is the force behind the internationally popular website, DoOneNiceThing.com, and has crafted a book of ideas and stories on how anyone, whatever their time or resources, can find a way to do something nice each week for their community, colleagues, children or the world at large.” [2]