The link below is to a previous discussion that took place here several years ago regarding this topic.

Rodney

Here is a link that might be useful: Are winter squash leaves edible?

Wow, learn something new every day!

Zucchini blossoms maybe, but leaves? No way, there are a lot of other alternatives before I'd resort to eating leaves of a zucchini plant.

Not poisonous, although I've never heard of people eating zucchini leaves. In Africa, pumpkin leaves are eaten and they are a close relative.

The young leaves with some stem can be quite good. Before they get fuzzy, prickly.
A better edible leaf is on the serpent or also called Cucuzzi. It is actually an edible gourd and has a smooth leaf. I prefer it so don't bother with the regular zuc leaves.

Last year the first frost was so late i had a whole second crop and did cut all the fresh growth for a meal but that is rare...

I also grow a variety that produces an unusual abundance of flower for stuffing...
A local nursery sells this seed provider so i grow a bit of these...
(good pole beans as well)

Here is a link that might be useful: Franchi