Three hundred cases in which both ultrasonic and soft tissue placentography examinations had been done are correlated with each other and the clinical findings. These are grouped in two series, one in 1972-1973 and the other 1973-1974. The accuracy rate for both methods was 95 per cent. Outright errors were 2 per cent, and cases in which correlation was lacking for reasons other than diagnostic errors were 3 per cent. Reasons for this lack of correlation are discussed and illustrated. Seven examples of the ascending (or migrating) placenta were also found and an illustrative case is described.