Background: Small for gestational age SGA) refers to foetuses with birth weight less than tenth centile for gestational age. The present study was two- dimensional sonographic placental measurements in the prediction of small for gestational age infants. Materials & Methods: 110 patients with singleton live pregnancy between 18 weeks 0 days to 23 weeks 6 days who visited from OBG department of JJMMC&H were included. Placenta was scanned from various angles to obtain the largest placental diameter possible- maximal placental diameter (MaxPD), and maximal placental thickness (MaxPT). Results: There were 60 AGA, 40 SGA and 10 LGA. The mean placental thickness in AGA patients was 25.4 mm, in SGA was 22.3 mm and in LGA was 36.8 mm. The maximum placental thickness in AGA was 26.8 mm, in SGA was 22.9 mm and in LGA was 37.4 mm. The difference was significant (P< 0.05). The mean placental diameters in AGA patients was 14.6 mm, in SGA was 11.2 mm and in LGA was 16.5 mm. The maximum placental thickness in AGA was 14.9 mm, in SGA was 12.6 mm and in LGA was 16.8 mm. The difference was significant (P< 0.05). Sensitivity (%), specificity (%), PPV (%) and NPV (%) for MPT ≤ 25.25 was 84.2, 62.5, 30.5 and 95.3. For MPD ≤ 12.95 was 85.2, 82.1, 48.5 and 96.2 and for MPT + MPD was 85.7, 65.9, 31.2 and 95.7 respectively. Conclusion: Placental measurements taken in mid-gestation are a valuable predictor of SGA. Measurement of placental diameter and thickness is quick and simple.