Clinical trials often involve multiple objectives related to multiple settings such as treatment arms, endpoints (primary, secondary, or tertiary), and subgroups. In such clinical trials, multiplicity issues caused by multiple statistical tests need to be adequately handled throughout studies. Novel statistical methods to account for several sources of multiplicity have been developed and applied in recent clinical trials. This article briefly reviews and summarizes the multiplicity issues in clinical trials that have multiple objectives and discusses the considerations in trial design, analysis, data interpretation, and the reporting of results. Relevant textbooks, articles, an international conference, guidances, and a web site are provided as references.