Objective To investigate the effect of etomidate on porcine adrenal cortical cells and the influence of preconditioning with small dose etomidate. Methods Porcine adrenal cortical cells were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 15% fetal bovine serum at 37℃ in 5% CO2 incubator for 24 h. The concentration was 2 × 106/ml. The experiment was performed in 2 parts. In part Ⅰ the cells were exposed to 50, 100, 200, 300, 400, 500 and 1000 mol/L etomidate respectively and incubated for 6, 12and 24 h, while in control group, the cells were exposed to 0.5% dimethylsulfoxide (DMSO). Cell viability was measured using CCK-8 assay and apoptosis by flow cytometry, and the 50% inhibitory concentration (IC50) of etomidate was calculated at 24 h of incubation. In part Ⅱ the cells were exposed to 0.6 μmol/L etomidate for 1 h and were allowed to recover for 4 h after etomidate washout, then etomidate 325 μmol/L was added and the cells were incubated for 24 h. Cell viability and apoptosis were assessed and the IC50 of etomidate was calculated as in part Ⅰ .Results Etomidate inhibited viability of porcine adrenal cortical cells and induced apoptosis in a dose- and time-dependent manner. The IC50 of etomidate at 24 h of incubation was 325 μmol/L. Preconditioning with0.6 μmol/L etomidate for 1 h attenuated the apoptosis induced by etomidate 325 μmol/L. Conclusion Etomidate can inhibit cell viability and induce apoptosis in a dose- and time-dependent manner. Preconditioning with small dose etomidate has protective effect.