Atypical antipsychotics are gradually more frequently being used in the bipolar disorder. In psychiatric patients, whose illness continues in the pregnancy period, the drug usage is controversial and while the case notifications increase, our information is updated. Olanzapine comes to the fore with both its antipsychotic activity and mood stabilizing activity. In this presentation, the usage of the olanzapine with success during and after the bipolar affective disorder manic episodes in a pregnant patient will be presented. A 32-year-old woman patient applied to our polyclinics with the complaints of the fearing from the humans, insomnia, talking a lot, energy increase, desire to spend a lot of money, hearing sounds. In the story taken from the patient, it was determined that she was monitored with the diagnosis of the bipolar affective disorder and used the treatments of lithium 900mg/day and risperidone2mg/g, however as she was pregnant, she stopped the drugs and she was 14 week pregnant. She was hospitalized. After being consulted with the department of the gynecological diseases and birth, by considering the ending of the first trimester and with the approval of the family, the olanzapine5mg/g treatment was started. In the follow-ups, the patient entered remission and the outpatient polyclinics continued her controls. She continued to use the olanzapine treatment until the end of the pregnancy. After the birth, any pathology was not determined in the baby. Now the baby is 2 years old and the healthy mother continued her treatment after the birth. The exacerbation of the symptoms in the psychiatric patients who remained without treatment during the pregnancy can give damages to the mother and baby. In the pregnant patient remaining without treatment, the irregular nutrition, cigarette, alcohol and substance use, attempts of giving damages to herself and the baby can be observed. In the literature, there are notifications of cases, which use olanzapine and give birth to the healthy baby as of the first trimester of the pregnancy. In a study that Goldstein and friends have realized, it has been declared that abortion has been determined in 17 of the 37 patients using olanzapine; however, no malformation has been determined in any one of 20 pregnant women giving birth. In our case, olanzapine has been used during the pregnancy and she gave birth to a healthy baby. In the two-year monitoring of the baby, any anomalies have not been determined. Due to the metabolic effects of the olanzapine, in the pregnant women using olanzapine, it should be monitored in terms of the gestational diabetes and excessive weight gain. Our case is a sample supporting the usage of olanzapine with success in pregnancy and it is compliant with the literature.