The concept of the 3 R's was developed over 50 years ago in 1959 by W.M.S. Russell and R.L. Burch. In 1986, the U.S. Office of Technology Assessment adopted the definition of the 3 R's. The 3 R's are Replacement, Reduction and Refinement, and are the guiding principles that underpin the humane use of animals in scientific research around the world. The purpose of the 3 R's is to show researchers and educators how alternatives to using animals in scientific research and education are possible. These principles can be extended to dissection in the science classroom, which is where our interest lies. This one page paper gives an explanation of what the 3 R's are, and gives you a chance to write down how you might use them in your classroom. Perhaps you are not ready or willing to give up dissection and replace it with something different such as a computer dissection simulation or paper dissection. Well, you can still follow the Reduction and Refinement guidelines by using less animals or by using them in a different way. I changed my viewpoint on dissection after 36 years of teaching Biology in the traditional way. I hope this will maybe give you something to think about.