The parasternal block is an ultrasound-guided interfascial plane block that provides anesthesia of the medial quadrants of the breast. The original approach provided injections in the fascial plane between the pectoral major and external intercostal muscles. We observed that this technique might limit an adequate diffusion of the injectate due to the anatomical convexity of the ribs, which might hinder fascial hydrodissection. We suggest a modified approach by positioning the tip of the needle on the rib dome to reduce the local anesthetic volume and obtain a more homogeneous and longitudinal spread into the target fascial compartment.