Not wood! However really well made, rounded edges.
Great Offer Stock states it's a wood. It is not and only because the quality of the finish is really good I have not called them to complain.
The important detail:
THE EDGES ARE ROUNDED OFF AND MAYBE HALF INCH WIDE. Beautiful.
Lots of other modular storage items are 3/4 of an inch and have edges that could slice your skin if you hit your knee of forehead.
Very easy to put it all together, I did it myself, two units (I covered one wall with them), my husband just came to admire.
THE BASKETS ARE DREADFUL AND MAKE A CHEAP DAYCARE LOOK. Exchange for wicker or woven stuff if you can find it in the sizes.
I wish Kidkraft had an option with woven baskets in the matching sizes, since IT IS HARD TO FIND BASKETS THAT ARE 5 INCH TALL (10 DEEP, AND 16 INCH/ 8 INCH WIDE)