Introduction- Rh isoimmunization occurs when a pregnant woman develops antibodies against paternally derived red cell antigens, which can harm the fetus by causing hemolysis and related complications. Traditional invasive diagnostic techniques like amniocentesis and cordocentesis are used to monitor at-risk fetuses. However, non-invasive Doppler ultrasound of the middle cerebral artery (MCA) offers a valuable alternative. Increased peak systolic velocity (PSV) in the MCA indicates foetalanaemia, with a PSV above 1.5 multiples of the median for gestational age detecting 88-90% of moderate to severe cases. This study aims to evaluate the effectiveness of MCA-PSV as a non-invasive predictor of foetalanaemia in non-hydropic foetuses affected by maternal red cell isoimmunization. Materials and Methods- This prospective study, conducted over a period of one year at a tertiary care centre, involved 26 Rh-negative pregnant women with positive Indirect Coomb’s tests. Doppler ultrasound assessed the middle cerebral artery (MCA) peak systolic velocity (PSV) in non-hydropicfoetuses, using a cut-off of 1.5 multiples of the median (MoM). The peak systolic velocity (PSV) in the middle cerebral artery (MCA) was assessed in all non-hydropicfoetuses, with measurements compared against a reference chart, using a cut-off of 1.5 multiples of the median (MoM). After delivery neonatal haemoglobin levels were analysed to define anaemia and compare with MCA-PSV values. Results-The study included 26 cases of Rh isoimmunization, diagnosed in the second trimester for 10 patients and in the third trimester for 16. Delivery methods comprised 15 vaginal births and 11 caesarean sections. The distribution of gestational age at delivery was as follows: 30-33 weeks (9 cases), 34-36 weeks (10 cases), and ≥37 weeks (7 cases).Doppler ultrasound of the middle cerebral artery (MCA) showed peak systolic velocity (PSV) above 1.5 MoM in 8 cases. Neonatal haemoglobin evaluations revealed normal levels in 7 cases and anaemia in 19 cases, including 4 with severe anaemia.Using the 1.5 MoM cutoff, the MCA-PSV demonstrated a sensitivity of 88.9%, specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 25%. Conclusion- Doppler ultrasound of the middle cerebral artery peak systolic velocity (MCA-PSV) serves as an effective non-invasive screening method for foetalanaemia in cases of Rh alloimmunization, replacing invasive techniques like amniocentesis and cordocentesis. Our study indicates that MCA-PSV is reliable for predicting foetalanaemia, potentially reducing the need for invasive interventions until intrauterine blood transfusion is necessary.