This soup features a variety of main ingredients, including shrimp, pork, chicken, and seafood.

[5] The soup base depends on the exact sub-type but is generally water, coconut milk, or chicken or other broth.

[6] When the meat is cooked, final flavorings whose taste is destroyed by heat, such as fish sauce and lime juice, are added.

For most varieties a paste called nam phrik phao (Thai: น้ำพริกเผา) is also added, made from shrimp, chilis, shallots, and garlic.

Depending on the type of tom som, the acidity can be derived from lime juice or from the use of tamarind.

[17][18] Another well-known and popular dish is tom saeb (ต้มแซ่บ), a spicy and sour soup originating from Northeastern Thailand (Isan).