This chapter aims to give detail about ethics and animals. These days, it is very important to understand ethical issues when we are dealing with research on animals and humans. Autonomy, beneficence, do not harm, and justice are four principles of ethics. Animal toxicity studies are done before drug can be tested in human beings. The toxicity studies are divided into three stages—acute toxicity studies (single dose studies), subacute toxicity studies (repeated dose studies), and chronic toxicity studies (long-term studies). The guidelines for performing experiments on animals are given by CPCSEA (committee for purpose of control and supervision on experiments on animals). The guidelines regarding maintenance of animal house are also given by CPCSEA. Institute Animal Ethics Committee is constituted by CPCSEA by appointing experts from the institute as well as from outside the institute. The IAEC functions as per SOP (standard operating procedures) of the CPCSEA. The committee is reconstituted every five years along with renewal of animal house registration. The committee reviews all the research plans involving animals.