Annual alligator (Alligator mississipiensis) nest counts were conducted in Louisiana coastal marshlands, 1970-1977. Alligator populations were projected from nest count transect data. Total estimated population ranged from a low of 135,000 to a high of 280,000. Highest population densities were located in the Chenier Plain Marsh Zone of southwest Louisiana. Alligator population density (1 alligaotr: 3.2 ha) was highest in the intermediate marsh type. The brackfish and fresh types were about equal with I alligator: 5.7 ha.