Prior studies have shown that powerful individuals are more unethical than powerless individuals. In real life, power is unstable, and multiple social interactions may cause loss of power. However, extant research has assumed the power structure to be stable and thus overlooked the potential interaction of power and stability in affecting unethicality. Using the approach-inhibition theory of power, we predicted that stability of power moderates power’s effect on unethical behavior. Results from four studies revealed that powerful individuals showed more unethical behavior than powerless individuals only when power was stable, but not when it was unstable. The higher level of unethical behavior under the condition of stable power was explained by attitude toward risk. Our results highlight that the link between power and unethicality is broken when power is unstable. Powerful individuals are no more unethical than powerless individuals when they face a greater possibility of losing their power.