Pistachio basics

Is a Pistachio a Nut or a Seed? The Botanical Answer

Botanically a seed, culinarily a nut. The clear answer to whether a pistachio is a nut or a seed — and why it matters.

Written by Elena Ricci, Founder & lead writer Published Updated

Quick answer

Botanically, a pistachio is a seed — specifically the seed of a fruit called a drupe, like almonds, cherries and peaches — not a true nut. Culinarily and for food labelling and allergies, however, it's classed and treated as a tree nut, so anyone with a tree nut allergy should avoid pistachios.

This is the companion to our what is a pistachio overview, answering the specific question people ask: is it a nut or a seed?

The botanical answer

Botanically, a pistachio is a seed — specifically the seed of a fruit called a drupe, the same family as almonds, cherries, peaches and olives. The "shell" is part of the fruit's stone. So the strict botanical answer is "seed of a drupe", not a true nut (true botanical nuts include hazelnuts and chestnuts).

The culinary and allergy answer

In the kitchen — and crucially for food labelling and allergies — pistachios are treated as tree nuts. That's the answer that matters for safety: anyone with a tree nut allergy should avoid pistachios and pistachio products, including pistachio milk.

Why the distinction matters

  • Cooking: pistachios behave like nuts, so recipes treat them that way.
  • Allergies: they're labelled and regulated as tree nuts — always heed that.
  • Trivia: it's why almonds and pistachios are botanically similar (both drupe seeds).

For more pistachio basics, see what is a pistachio and why pistachios are green.

Frequently asked questions

Is a pistachio a nut or a seed?
Botanically, a pistachio is the seed of a fruit called a drupe — the same category as almonds, cherries and peaches. Culinarily and for allergy purposes, it's treated as a tree nut. So the everyday answer is 'a nut', and the botanical answer is 'the seed of a drupe'.
Are pistachios safe if I have a tree nut allergy?
No. Even though pistachios are botanically seeds of a drupe, they are classed and labelled as tree nuts and can trigger tree-nut allergies. Anyone with a tree nut allergy should avoid pistachios and pistachio products, including pistachio milk.