Background: To date there has been no study done in Saudi Arabia  to identify the risk factors for poor outcome of H1N1 infection in pregnancy. Objectives: we aimed to evaluate the epidemiological data, clinical course, treatment modalities, and maternal and fetal outcomes of 33 pregnant women diagnosed with H1N1 Influenza A in a referral maternity and children hospital at Al- Madinah Saudi Arabia on the period from June 2009 till February 2010. Methods: This retrospective cohort study reported 33 pregnant women (9.1% primigravida) aged 27.7±5.6 years who were laboratory-confirmed cases diagnosed with H1N1 Influenza A in a referral maternity and children hospital at Al- Madinah Saudi Arabia on the period from June 2009 till February 2010. Their mean gestation age was 23.5±10.9 weeks with history of bronchial asthma in 45.5%. Results: The mean duration between symptoms' onset and hospital presentation was 5.0±2.2 days with late presentation in 10 cases (30,3%). Large number of cases presented with fever more than 39 (24 (72.7%), sore-throat (24 (72.7%) and cough (29 (87.9%) while 19 patients presented with dyspnea (57.6%). Pregnant patients with H1N1 received Tamiflu (oseltamivir)) from 2 to 7 days with a mean of 4.7±1.3 days. They stayed at hospital for variable periods from 2 to 28 days with a mean of 7.9±6.6 days (Table 4). Most patients (31(93.9%)) received antibiotics. Maternal poor outcome included hypoxia in 6 patients (18.2%), ICU admission for 2-3 days with mechanical ventilation in 4(12.1%)). The main fetal poor outcome was intrauterine fetal death in 2 (6.1%) babies  . Conclusion: The main presentation of H1N1 among pregnant women was typical influenza-like illness. Considerable percentage of  patients presented late (30.3%). The duration of hospital admission is variable up to 28 days. Bronchial asthma was prevalent (45.5%) among pregnant women with H1N1 infection. The main poor outcomes were maternal respiratory failure (18.2%) and intrauterine fetal death (6.1%). There is increased   risk of intrauterine fetal mortality (6.1%) rather than materanl mortality (0%) .