Scientists, in addition to writing about their work, often give lectures and talks at conferences and meetings. Such presentations are an important part of scientific communication and many students are now required, during their course, to present short illustrated talks. For example, if you have recently completed a project or dissertation you may be expected to talk about it to the rest of the class. The length for the talk may vary, but it is usually between 15 and 30 minutes, with time allowed at the end for questions from the audience. The talks may be marked and the marks count towards the final assessment in a subject. Like other aspects of studying science, certain skills are involved and this chapter offers the advice needed. The subjects covered include: • the role of the audience • format of a talk • preparation (including the use of visual aids) • final preparation and delivery • assessment.