Background: Anemia is a public health concern among Mexican women and children, particularly among those of low socioeconomic status and indigenous heritage. Conducting research among vulnerable populations requires a dependable, long-term relationship with community support and engagement. Thus, Viajes Interinstitucional de Integración, Docente, Asistencia y de Investigación [VIIDAI] (Inter-institutional Field Experiences for Integration, Teaching, Medical Service, and Research), a partnership between universities, non-governmental organizations, and a rural Mexican community was utilized to investigate the prevalence, correlates, and etiology of anemia in a rural region of Baja California, Mexico. Methods: In affiliation with VIIDAI, a series of cross-sectional studies were performed. Women (15-49 years) and their children (6-59 months) were invited to participate. Data collection occurred at three time points: 2004-2005 (Wave 1), 2011-2012 (Wave 2), and 2012 (Wave 3). In each wave, participants were randomly selected and completed a survey containing demographic, socioeconomic, health, and dietary characteristics and provided a capillary blood sample for anemia testing. A portable HemoCue was used to measure hemoglobin and diagnose anemia; peripheral blood smears were prepared for anemic participants. In Wave 3, venous blood was collected for laboratory testing that elucidated the etiology of anemia. Nutrition education, community health interventions, and clinical health evaluations were offered to residents following Wave 1 and continuing through Wave 3. Results: Waves 1, 2, and 3, included 201, 146, and 118 women, and 99, 77, and 25 children, respectively. Prevalence of anemia decreased from 42.3% to 23.3% between Waves 1 and 2 in women (p<0.001), from 46.5% to 30.2% in children 24-59 months (p=0.066), and from 71.4% to 45.8% in children 6-23 months (p=0.061). In Wave 1, the consumption of foods that enhance iron absorption (e.g. leafy, green vegetables and fruits high in vitamin C) was protective against anemia (p=0.043). Vitamin supplementation was protective against anemia in Wave 3 (OR=0.12, 95% CI 0.02-0.94). In Wave 3, iron deficiency anemia was the primary etiology in 100% of children and 80.8% of women, followed by vitamin B-12 deficiency (11.5%) and combined iron and vitamin B-12 deficiency (7.7%). Conclusions: Substantial reductions in anemia prevalence were observed. However, nutrition education and improved access to nourishing foods are essential to further reducing anemia prevalence.