The dry fruits are known as coriander seeds. In Indian cuisine they are called dhania.

The word coriander in food preparation may refer solely to these seeds (as a spice), rather than to the plant. The seeds have a lemony citrus flavour when crushed, due to terpeneslinalool and pinene. It is described as warm, nutty, spicy, and orange-flavoured.

The nutritional profile of coriander seed is different from the fresh stems and leaves, the vitamin content being less than amounts being displayed in the chart above for the plant, with some being absent entirely. However, the seeds do provide significant amounts of calcium, iron, magnesium, and manganese.

The variety C. s. vulgare has a fruit diameter of 3–5 mm (0.12–0.20 in), while var.microcarpum fruits have a diameter of 1.5–3 mm (0.059–0.12 in). Large-fruited types are grown mainly by tropical and subtropical countries, e.g. Morocco, India and Australia, and contain a low volatile oil content (0.1-0.4%). They are used extensively for grinding and blending purposes in the spice trade. Types with smaller fruit are produced in temperate regions and usually have a volatile oil content of around 0.4-1.8%, so are highly valued as a raw material for the preparation of essential oil.

It is commonly found both as whole dried seeds and in ground form. Seeds can be roasted or heated on a dry pan briefly before grinding to enhance and alter the aroma. Ground coriander seed loses flavour quickly in storage and is best ground fresh.

Coriander seed is a spice in garam masala and Indian curries, which often employ the ground fruits in generous amounts together withcumin. It acts as a thickener.

Roasted coriander seeds, called dhana dal, are eaten as a snack. They are the main ingredient of the two south Indian dishes:sambhar and rasam. Coriander seeds are boiled with water and drunk as indigenous medicine for colds.