Crayfish are eaten all over the world. Like other edible crustaceans, only a small portion of the body of a crayfish is edible. In most prepared dishes, such as soups, bisques and étouffées, only the tail portion is served. At crawfish boils or other meals where the entire body of the crayfish is presented, other portions may be eaten.

Claws of larger boiled specimens are often pulled apart to access the meat inside. Another favourite is to suck the head of the crayfish, as seasoning and flavour can collect in the fat of the boiled interior. A popular double entendre laden phrase heard around crawfish season in Louisiana derives from this practice: "suck the head; pinch the tail".

A common myth is that a crawfish with a straight tail died before it was boiled and is not safe to eat. In reality, crawfish that died before boiling can have curled tails as well as straight, as can those that were alive, and may very well be fine to eat. Boiled crawfish which died before boiling are safe to eat if they were kept chilled before boiling and were not dead for a long time. (This does not mean that a sack of crawfish that are all dead should be boiled.) A much better test than the straight tail as to the edibility of any crawfish is the tail meat itself; if it is mushy, it is usually an indication that it should be avoided.

Like all crustaceans, crayfish are not kosher because they are aquatic animals that do not have both fins and scales. They are therefore not eaten by observant Jews.

Scandinavia

Crayfish is a popular dish in Sweden and Finland, and is by tradition primarily consumed during the fishing season in August. The boil is typically flavored with salt, sugar, ale, and large quantities of the flowers of the dill plant. While most Americans eat them warm, the Swedish and Finnish normally eat them cold. The catch of domestic freshwater crayfish, Astacus astacus, and even of a transplanted American species, Pacifastacus leniusculus, is very limited, and to satisfy demand, the majority of what is consumed has to be imported. Sales depended on imports from Turkey for several decades, but after a decline in supply, China and the United States are today the biggest sources of import.