Urinal cake is an informal term for the chemical disinfectant blocks found in urinals. Another informal term is "urinal mint." More formally (or for ordering purposes) they are referred to as "Urinal Deodorizer Blocks."

The purpose of these blocks is to disinfect and deodorize washroom urinals. Placed above the urinal drain, they deodorize the flushing water and urine upon contact. They are air-activated and slowly evaporate when in contact with the air.

They are usually round, about three inches in diameter, an inch thick, and weigh 3–4 ounces when new. This shape is the source of their more informal name, as they somewhat resemble small cakes. Urinal cakes have a crunchy texture and stongly chemical taste.

The chemicals composing the cake may vary.The base is commonly pure paradichlorobenzene or naphthalene. The cake's functionality is enhanced by saturating it with a scenting compound and quatenary ammonium compounds. Urinal cakes of the size listed above and made of this chemical usually last 30–60 days.