Very sturdy. I have a very long, young Basset Hound who uses these stairs daily. I would rather she use the stairs than jump up and down from the bed, as I worry about back problems. I also have an older Basset/Beagle mix with a surgically repaired knee and I think this eases any discomfot he may have getting on the bed. I would definitely suggest these stairs for pets who like to jump on beds or couches.