Results of c/a variation under pressure for zinc from total-energy calculations that use first-principles linearized-muffin-tin-orbital calculations are presented. c/a decreases with compression and is found to change slope around V/${\mathit{V}}_{0}$\ensuremath{\approxeq}0.92, to approach the ideal value of c/a=1.63. This behavior is compared with existing experimental data and with full-potential linearized-augmented-plane-wave calculations.