Bird Richness of Pantanos de Villa wildlife refugee, Chorrillos, Lima, Peru was documented, aperiodically between November 2004 to August 2007 employing 10 surveys by visual detection. The avian richness was 58 species, belonging to 47 genera, 26 families and 12 orders. Jacknife of first and second order and Chao-1 estimators of species richness indicated that could be registered at least 25, 43 and 56 more species and could be detected 69.8, 57.4 and 50.8%, respectively, of possible species that can occur in the study zone. The highest species richness and the higher value of Shannon index were recorded in August 2006 and in September 2006, respectively. November 2004, March 2005 and June 2007 censuses showed the lowest similarities of bird species according to Morisita-Horn and Sörensen indexes. By their seasonality, 36 species were residents, 6 local migratory, 3 Andean migratory and 16 continental migratory. Out of the species registered 2 were considered in danger, 1 vulnerable and 1 nearly threatened. Eight species were more frequent and abundant: Phalacrocorax brasilianus (Humboldt, 1805) (Phalacrocoracidae) (20.3%), Leucophaeus pipixcans (Wagler, 1831) (Laridae) (14.9%) Egretta thula (Molina, 1782) (Ardeidae) (12.7%), Chroicocephalus cirrocephalus (Vieollot, 1818) (Laridae) (9.8%), Ardea alba (Linnaeus, 1758) (Ardeidae) (5.6%), Fulica ardesiaca (Linnaeus, 1758) (Rallidae) (4.5%), Coragyps atratus (Beichstein, 1793) (Cathartidae) (3.7%) and Gallinula chloropus (Linnaeus, 1758) (Rallidae) (2.5%) representing 74% of total bird diversity.