'Beauty' is not a word typically associated with science. Nevertheless, numerous scientists in recent years have expounded on the role of beauty in science. These writings tend to be largely concentrated in theoretical physics. But what role does beauty play in the biological sciences? To answer this question, this article analyzes data from a large international study of scientists working at PhD-granting institutions in the US, UK, Italy, and India. Drawing on nationally representative surveys (N=1381) and in-depth interviews (N=104) with biologists in the sample, the article summarizes what 'beauty' means to biologists, where they encounter beauty in the practice of science, where in the scientific process they see aesthetic factors as relevant, and what they see as the consequences of encountering beauty in scientific work. The results show that most biologists in the four countries encounter beauty in the phenomena they study, and associate beauty primarily with the inner logic of systems. Most also find beauty relevant to presenting and analyzing results, and see it as a motivation for teaching as well as for pursuing scientific careers. While most biologists think it is important for scientists to encounter beauty in their work, they do not see it as always necessary or achievable.