Numbers of the California Brown Pelican (Pelecanus occidentalis californicus) off southern California declined precipitously during the 1960s (Schreiber and Delong 1969, Gress and Anderson 1983). With the decline in dichlorodiphenyltrichloroethane (DDT) in the marine food chain along with efforts to preserve key habitat, Brown Pelican populations in southern California have increased (Shields 2002). Although patterns of attendance at each colony vary greatly from year to year, breeding populations farther south along the west coast of Baja California and in the Gulf of California have remained fairly stable (Everett and Anderson 1991, D. W. Anderson pers. comm.). In 2004 Brown Pelicans formed a small nesting colony on Isla Alcatraz, a small island located 1.4 km off the coastal town of Bahía de Kino Viejo in Sonora, México (28° 49′ N, 111° 55′ W). I monitored this colony throughout the 2006 breeding season to determine if it had expanded or declined in comparison to previous estimates of numbers of active nests. I also tried to determine the fledging success of the colony by monitoring 40 focal nests from early in the season in January to when nests were abandoned in May. Given its small size, short distance from a major human settlement, and high biodiversity, Isla Alcatraz should be considered an important site for research and conservation.