Anemia and iron deficiency (ID) can impair quality of life and socioeconomic development. We evaluated the prevalence of anemia and ID in the adult Portuguese population in real-life contexts by gender, age, and pregnancy status. We performed a cross-sectional screening in adult individuals in mainland Portugal from 2013 to 2017. Participants completed a survey about demographics and signs or symptoms compatible with anemia, and ID and hemoglobin and ferritin concentrations were determined by point-of-care tests. We estimated and compared prevalence ratios (PR) of anemia and ID using Poisson regression with robust variance and the Wald chi-square test. We collected data from 11,030 individuals (26% men, 64% nonpregnant women, and 10% pregnant women). We found anemia in 51.8% (95% CI 50.1-53.4%) of nonpregnant women in fertile age, 46.6% (95% CI 44.7-48.6%) of nonpregnant women >51 years, 38.2% (95% CI 35.4-41.1%) of pregnant women, and 33.3% (95% CI 31.6-35.1%) of men. The prevalence of ID was 72.9% (95% CI 71.4-74.4%) in nonpregnant women in fertile age, 50.5% (95% CI 48.5-52.4%) in nonpregnant women >51 years, 94.8% (95% CI 93.3-96.0%) in pregnant women, and 28.9% (95% CI 27.3-30.6%) in men. We found significant associations between the prevalence of anemia or ID and nonpregnant women (PR: 1.50, 95% CI 1.42-1.59 or PR: 2.21, 95% CI 2.09-2.35, respectively), manifestation of signs or symptoms (PR: 1.19, 95% CI 1.53-1.23 or PR: 1.22, 95% CI 1.18-1.26), pregnant women (PR: 0.74, 95% CI 0.68-0.80 or PR: 1.30, 95% CI 1.27-1.33), and nonpregnant women ≤51 years (PR: 1.11, 95% CI 1.06-1.17 or PR: 1.42, 95% CI 1.36-1.48). In conclusion, anemia and ID represent moderate to severe public health problems, particularly among women in fertile age and in 3rd trimester, of pregnancy emphasizing the need to raise the public and health professionals' awareness of these problems and their prevention, diagnosis, and treatment.