Fourty five patients with ovarian tumours were studied for their sonographic morphological characteristics and were followed up with histopathological report for correlation between most important sonographic features of benign and malignant ovarian tumours. Among different features, thin wall, smooth inner wall structure and anechogenicity or low echogenicity of the lesions were more important features of benign tumours. Complex mass without demonstrable wall, indistinct inner wall structure and highly echogenic lesion with solid component were predictors of malignancy.