This paper discusses the need for consistency in mass-gathering data collection and biomedical reporting. Mass gatherings occur frequently throughout the world, and having an understanding of the complexities of mass gatherings is important to inform health services about the possible required health resources. Factors within the environmental, psychosocial and biomedical domains influence the usage of health services at mass gatherings. The biomedical domain includes the categorization of presenting injury or illness, and rates such as patient presentation rate, transferred to hospital rate and referred to hospital rate. These rates provide insight into the usage of onsite health services, prehospital ambulance services. and hospital emergency department services. Within the literature, these rates are reported in a manner that is varied, haphazard and author dependent. This paper proposes moving away from an author-dependent practice of collection and reporting of data. An expert consensus approach is proposed as a means of further developing mass-gathering theory and moving beyond the current situation of reporting on individual case studies. To achieve this, a minimum data set with a data dictionary is proposed in an effort to generate conversation about a possible agreed minimum amount and type of information that should be collected consistently for research and evaluation at mass gatherings. Finally, this paper outlines future opportunities that will emerge from the consistent collection and reporting of mass-gathering data, including the possibility for meta-analysis, comparison of events across societies and modeling of various rates to inform health services.