Given the increased diversity of the population in the United States and the importance of early science, technology, engineering, and mathematics (STEM) learning, it is crucial to identify ways to reduce racial, ethnic, and gender disparities in STEM education. This is particularly important for children with disabilities with intersecting identities, who are more likely to experience opportunity gaps in STEM. One way to address the issue of inequitable STEM learning opportunities is to make sure that research on evidence-based strategies is conducted with a wide range of children with diverse needs and characteristics, so that they can be generalized in real-life settings. To date, little is known about the representation of participants in the early STEM intervention literature. This review analyzed demographic reporting practices and participants' demographic characteristics in the early STEM intervention literature. The findings suggest that there is a lack of consistency in the reporting of demographic data, particularly regarding race and ethnicity. This inconsistency presents a potential challenge to the field, as it may hinder progress toward achieving equity and reducing disparities in early STEM education. This review highlights the urgent need to establish a consistent method for collecting and reporting participants' demographic data.