This study was carried out in the animal house of the College of Science at the University of Kufa from 15/11/2021 to 15/5/2022for the purpose of studying the harmful histological effects of the preservative sodium nitrite in some organs (livers, kidneys and brains) of fetuses during gestation (16,20 days) and during the three stages of gestation (7,16,20) days respectively of pregnant female rats that were treated with sodium nitrite,45 pregnant rat female of Rattns rattus type (Sprague Dawley) whose averages weights were (230) g and ages were (12) weeks, pregnant rats were divided into 3 main groups and each group contained 15 pregnant females: the first group was treated with physiological salt solution and was as a control group, while the second group was dosed sodium nitrite at a concentration of 10 mg/kg of body weight, while the third group was dosed sodium nitrite at a concentration of 15 mg/kg of body weight, each of the main groups was divided into 3 secondary groups, each of which included 5 pregnant rats, the first, second and third secondary groups from each main groups were dissected during (7,16,20) days of gestation, respectively,,,,