Abstract: Observational studies provide crucial information early during epidemics and pandemics, but they often suffer from methodological shortcomings, which can be resolved. Scientific research is a necessary part of epidemic preparedness and response. Observational studies, in which the intervention and outcome(s) of interest are not under the researcher’s control, are used in epidemics to describe basic properties of a pathogen and its transmission; clinical symptoms; associations between interventions and patient outcomes; and the effectiveness of public health measures to curb disease spread.