Introduction: Anxiety and depression are prevalent during pregnancy. Estimates of the prevalence of anxiety and depression during pregnancy vary according to the criteria used, variable methodologies and population characteristics. Methods: A cross-sectional survey design was used. A total of 175 antenatal mothers participated. Their socio-demographic and obstetric histories were recorded. The Hospital Anxiety and Depression Scale (HADS) and Mini International Neuropsychiatric Interview (M.I.N.I.) were used. Results: The prevalence of anxiety and depression disorders among antenatal mothers using diagnostic clinical interview were 9.1% and 8.6%, respectively. Factors associated with antenatal anxiety were marital status (being unmarried), positive history of mental illness, gestational age (<20 weeks), unplanned pregnancy and depressive comorbidity. However, only gestational age of less than 20 weeks and depressive disorder remained significant factors in the multivariate analysis. Discussion: The prevalence rate of antenatal depression detected by HADS screening was comparable to the rate from diagnostic interview, but there was a slight overestimation for antenatal anxiety. Nonetheless, HADS as a screening tool offers a practical solution for detecting these two conditions in a busy antenatal clinic or a large epidemiological survey. In view of the deleterious effects of antenatal anxiety and depression on mothers and children, these two conditions should be screened and managed appropriately.