It was rather easy to put together. It is a little wobbly but none-the-less my cats still seem to like it.    The only negative and I do believe I saw this in other reviews is the design has some flaws....from a cats perspective it isn't easy to get from every level.....my cats do it but it is rather entertaining as it seems to be a bit of a struggle and they have to get rather creative on how they get from the middle condo area to the next layer up.   I have cats ranging from 8 pounds to 18 pounds and they all enjoy it.