The current study aimed to screen the growth and viability of embryo from Day 21 to Day 56 post-breeding in Egyptian buffaloes. Twenty buffaloes were synchronized and examined serially by means of real-time B-mode ultrasound equipped with 12 MHz endorectal transducer. The developing embryonic sac diameter (ESD), crown rump length (CRL), head diameter (HD), trunk diameter (TD), and eye ball diameter (EBD) were measured. The heart rate and cardiac blood flow were sequentially examined to verify the fetal viability using color Doppler mode. Data showed the feasibility of first detection and measurement of ESD, CRL, HD, TD and EBD from Day 24.33 ± 0.67, 27.00 ± 1.73, 34.67 ± 1.76, 34.67 ± 0.88 and 33.67 ± 0.88, respectively. The fetal heart rate was 232.00 ± 12.35 beat/min at the day of first examination (Day 24.50 ± 1.30) after breeding. The cardiac blood flow was examined from Day 27 onwards. A highly significant (P< 0.0001) correlations were recorded between the ESD (r²=0.55), CRL (r²=0.85), HD (r²=0.85), TD (r²=0.93) and EBD (r²=0.85) and fetal age in buffaloes. It could be concluded that the high-frequency ultrasonography is a valuable diagnostic tool for the detection of early pregnancy from Day 24-26 post-breeding in Egyptian buffaloes. Verification of fetal heart beating (starting from Day 24-26) and cardiac blood flow (starting from Day 26-27) provide a reliable non-invasive promising technique for the fetal viability evaluation. The high correlation between TD and fetal age signified its clinical value, over other estimated fetometric parameters, in determining gestation period in Egyptian buffaloes during early pregnancy.