Fat injection for soft tissue augmentation is a common procedure in plastic surgery. Because the limitation of fat injection is its resorption, understanding how different handling techniques affect adipocyte survival is crucial to optimizing long-term results. In this study; we sought to determine the effect of aspiration and injection cannula diameters on adipocyte viability. Fat aspiration samples were obtained from 6 female patients undergoing abdominoplasty. Viable adipocytes were counted at fat suspension, which was obtained with 2-, 3-, and 4-mm-diameter aspiration cannulas and injected with 1.6-, 2-, and 2.5-mm-diameter injection cannulas. A greater number of viable adipocytes were detected using a 4-mm-diameter aspiration cannula (419 x 10(4) cell/1 mL, P < .05) and a 2.5-mm-diameter injection cannula (410 x 10(4) cell/1 mL, P < .05). The use of wider-diameter cannulas can potentially improve fat graft survival and reduce fat graft resorption.