Abstract: Pregnancy is a dynamic process characterized by multiple physiological changes in the cardiovascular system. These changes are adaptive mechanisms to face the high metabolic demand for both fetus and mother. Measurement of arterial blood pressure is important in each Ante-Natal Care (ANC) visit to categorize pregnant ladies for early detection and management of Pregnancy Induced Hypertension (PIH) cases. There are no reference values of arterial blood pressure among healthy Sudanese pregnant ladies and the values of blood pressure were obtained from international studies also fasting Ramadan can affect the blood pressure, blood glucose and body mass index. This study aimed at determining the effect of Fasting on the arterial blood pressure among healthy pregnant and non-pregnant Sudanese ladies living in Khartoum state. A case control study was conducted in Khartoum state during May-October, 2019 on (105) healthy Sudanese ladies who were randomly selected, their age range between 17-40 years. About 20 of them served as control group (non pregnant and not fasting) and (55) of them were pregnant not fasting and (30) fasting pregnant ladies as cases. All participants were assessed by questionnaire after filling an informed consent. Blood pressure was measured 3 times at resting state according to WHO criteria. In the fasting groups the blood pressure was measured before 3 pm. Data was analyzed using the Statistical Package for the Social Sciences (SPSS) Version 25 with significant p#0.05, comparing the fasting pregnant blood pressures with the non fasting. The blood pressure was found to be 100.6/67.8 mmHg in pregnant women, not fasting, 114.2/75 mmHg in non pregnant and 103.6/67.9 mmHg in fasting pregnant ladies. In the pregnant not fasting group the blood pressure was found to be 94.7(±7.5)/63(±5.9 mm Hg) for first trimester, 100.4 (± 9.2)/67.2(±7.9 mmHg )for second trimester and 105.4 (± 13.2)/72.2(±7.3 mmHg) for the third trimester. While for the fasting group the blood pressure was found to be 104.6 (±15.1)/70.4(±14.2 mmHg) in the first trimester, 96.4 (±6.7)/63.8(±4.6 mmHg) in the second trimester and 109.7(±13.2)/69.4 mmHg (±9.7) in the third trimester. The results of this study showed that the pregnancy affects blood pressure significantly and the BP is lower in the first trimester than second trimester and the BP in the second trimester is lower than the third trimester. The mean of systolic and diastolic blood in the fasting group were higher than the mean systolic and diastolic blood pressures in non fasting group. The highest mean systolic blood pressure was recorded at the third trimester and the highest mean diastolic blood pressure recorded at the first trimester. Antenatal care follow up according to reference values for Sudanese ladies is important for the early detection and management of pregnancy induced hypertension. Further confirmatory studies are needed.