The relationships between CEUS parameters of adnexal tumours and postoperative immunohistochemical assessments of CD34, CD105 and bcl-2 were analysed. This study aimed to investigate whether contrast-enhanced ultrasonography (CEUS) parameters depend on the microvascular density of the tumour lesion found after surgery. Fifty-one patients with a diagnosis of adnexal tumours were included in this single-centre, prospective study. Participants underwent preoperative CEUS (contrast-enhanced ultrasound). Colour Doppler enhancement characterisation parameters (Ystart, Ymax and S) were determined. Immunohistochemical examination of histological specimens of the adnexal lesions was then carried out to determine the expression levels of the CD34, CD105 and bcl-2 proteins. Relationships between the aforementioned parameters were investigated. No significant statistical correlations were observed between CD34, CD105 and bcl2 expression levels and CEUS parameters, independently of whether the operated lesion was malignant or benign. Transvaginal CEUS is diagnostic for the detection of pathological neoplastic vascularisation of an adnexal lesion independent of the density of microcapillaries found postoperatively.