One of the pivotal issues in scientific research is to consider ethics in animal experimentation. Animal research had a pivotal contribution to a large number of scientific advances of the past century and continues to aid our understanding of various diseases. Issues raised by research involving animals have aroused intense debate. Discussion on the subject is often portrayed as being essentially between two positions that are either ‘for’ or ‘against’ the use of animals. This is unhelpful, since the matter itself is complex, as are the many views that surround it. One group favours the use of animals in research and emphasizes the scientific and medical benefits that have arisen. Others are less focused on the scientific issues, and more concerned with the fundamental ethical question of whether it is right for humans to subject sentient animals to procedures that may cause them pain and suffering, and from which they will not benefit. This review discusses the need for animal experimentation and ethical issues related to animal research.