Objective: To identify the factors associated with anemia in pregnant women hospitalized in the gynecology and obstetrics service of the "San José" Callao-Lima hospital. Material and methods: observational, analytical, cross-sectional study with retrospective data collection.  Results: we found a prevalence of 78.9% of anemia in pregnant women. Pregnant women in the 1st trimester had a higher percentage of anemia (38.6%) (p = 0.00); 54.6% of pregnant women under 30 years old had anemia (p = 0.01), the odds for age was 2.2; Pregnant women with a BMI of 25 to 29.9 were the ones with the highest percentage of anemia (36.3%) (p = 0.29); The multiparous pregnant women were the ones that presented greater anemia (61.7%) (p = 0.03), the odds for parity was 1.83; pregnant women without NPC had a higher percentage of anemia (64.9%) (p = 0.00), the calculated odds were 0.03; pregnant wo...