The indications, advantages, and disadvantages of round and anatomical implants have previously been described. The principles of biodimensional implant selection have been developed by several authors, where the objective choice of breast prosthesis for augmentation is based on the patient's breast tissues. This process has largely been applied to anatomical implant selection. We report a case of breast asymmetry, where we have applied the same concepts in the selection of implants based on tissue dimension. This resulted in an anatomical implant being used to augment the left breast, and a round implant on the right. To our knowledge a round implant and an anatomical implant have not previously been employed in the same patient to correct breast asymmetry. This resulted in excellent postoperative symmetry.