Background: Iron deficiency anemia (IDA), as one of the most common problems of the elderly, is preventable and treatable. Objectives: The current study aimed at determining the prevalence of IDA and its related factors in older females and comparing it between community-dwelling individuals and nursing home residents in the Southwest of Iran. Methods: The current cross sectional study was conducted on 365 community-dwelling and nursing home residents in Bushehr Province, Iran. Data were collected in 2017. Blood samples were taken from all participants to measure hemoglobin and ferritin levels. Hemoglobin values less than 12 g/dL were considered as diagnostic criteria for anemia. Simple logistic regression was used to compare normal subjects with the ones with anemia, and after adjusting the marital status and age, the odds ratio (OR) was obtained. Furthermore, independent variables affecting them and ORs and their associated confidence intervals (CIs) were obtained, which were significant. Data were analyzed using SPSS software and the significant level was less than 0.05. Results: The mean ± SD age of participants was 82.00 ± 5.79 years, and the means of hemoglobin and ferritin levels were 12.6 ± 1.04 g/dL and 15.00 ± 5.11 µg/dL, respectively. Based on the hemoglobin rate, 30% of the elderly females had anemia, and the prevalence of IDA in the elderly living in the community and nursing homes was 27% and 39%, respectively. Conclusions: The prevalence of IDA in elderly females was high in Southwest of Bushehr. The crude and adapted ORs indicated that living in the nursing home was a risk factor for anemia. Therefore, this ailment requires a national screening, diagnosis, and early intervention.