Demographic studies can show overall population performance, help understand population structure and recognize animal distribution and movement. In order to investigate the social structure of giraffes in the Tarangire-Manyara Ecosystem, data on population structure, sex ratios, age ratios and habitat preference were examined in three protected areas. These areas included Lake Manyara National Park, Manyara Ranch and Tarangire National Park. A total of 348 giraffes were sexed and aged in the three areas combined. Manyara Ranch had the largest maximum number of giraffes seen in one day with 85 individuals. The population was significantly skewed towards adult female giraffes, which comprised the majority of the population studied. The population performance is low since there is an apparent lack of reproductive success within the population due to the high presence of adult females compared to young. The most common group type in which individual giraffes dwelled in was mixed groups. The mean group size of giraffes was significantly largest in Manyara Ranch, which may indicate a higher concentration of resources in the area. Further study in the future should investigate the relation of body condition and activity patterns to social dynamics in order to reveal the essential factors that affect the overall performance of the giraffe population.