Between April and July 2007 we surveyed the coasts of Jalisco, Colima, Michoacán and Guerrero, in southwestern Mexico. We documented 33 breeding localities of seven species of Charadriiformes: six of Snowy Plover, two of Collared Plover, five of Wilson's Plover, three of Killdeer, one of Gull-billed Tern, and 16 of the Least Tern. We also located a potential colony of the Black Skimmer. Twenty of these locations were documented for the first time. Excepting breeding localities of the Killdeer and three-four of the Least Tern, all colonies were on salt-flats, likely due to the sand dunes bordering beaches being narrow, well vegetated and used heavily by humans, or, for Snowy Plovers, perhaps owing to greater food availability on saltflats. Our data elevated the conservation value of Laguna Cuyutlán, Colima, and discovered the value of the Xola-Paramán system, in Jalisco, and Laguna El Potosí system and La Parota, in Guerrero.