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 labeling 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 above all for food labeling 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 labeled and regulated as tree nuts, so 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 labeled as tree nuts and can trigger tree-nut allergies. Anyone with a tree nut allergy should avoid pistachios and pistachio products, including pistachio milk.