To compare the diagnostic efficacies of B-mode ultrasound (US), strain elastography (SE), contrast-enhanced ultrasound (CEUS) and the combination of these modalities for breast lesions < 1 cm in size. Between January 2013 and October 2015, 203 inpatients with 209 sub-centimetre breast lesions categorised as BI-RADS-US (Breast Imaging Reporting and Data System for Ultrasound) 3-5 were included. US, SE and CEUS were performed to evaluate each lesion. The diagnostic performances of different ultrasonic modalities were compared. The diagnostic efficacies of BI-RADS-US and our re-rating systems were also compared. The pathology findings were used as the reference standard. The specificities of US, SE and CEUS for tumour differentiation were 17.4 %, 56.2 % and 86.0 %, respectively (P < 0.05); and the sensitivities were 100 %, 93.2 % and 93.2 % for US, SE and CEUS, respectively (P < 0.05). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was 0.867 for original BI-RADS-US, 0.882 for BI-RADS-US combined with only SE, 0.953 for BI-RADS-US combined with only CEUS and 0.924 for BI-RADS-US combined with both SE and CEUS. The best combination was BI-RADS-US combined with only CEUS. Evaluating sub-centimetre breast lesions with SE and CEUS could increase the diagnostic specificity while retaining high sensitivity compared with B-mode ultrasound. aEuro cent Evaluating breast lesions with SE and CEUS could increase the diagnostic specificity aEuro cent SE and CEUS offer alternatives to biopsy and possibly allow shorter-interval follow-ups aEuro cent BI-RADS-US combined with CEUS exhibited the best diagnostic performance.