The Epidemic Intelligence Service officers (EISOs) at the National Center for Environmental Health (NCEH)/Agency for Toxic Substances and Disease Registry (ATSDR) respond to public health outbreaks, assist public health surveillance, and recommend public health actions. We summarize the breadth of work done by EISOs assigned to NCEH/ATSDR during 2006-2015. We used the Web of Science, Scopus, and PubMed databases to identify articles authored by the EISOs, number and types of epidemiologic assistance field investigations (Epi-Aids), and interviewed NCEH/ATSDR programs with EISO assignees. The largest number of NCEH/ATSDR EISO publications (n = 61) and Epi-Aids (n = 110) related to toxic chemicals (23 and 37, respectively), followed by natural disasters and those caused by humans (19 and 25, respectively), extreme temperature-related illness (9), and chronic diseases (8). The investigations raised awareness, identified risk factors and public health needs, and introduced better prevention and protection measures for human health. Through field investigations and other technical assistance, NCEH/ATSDR provided leadership and staff scientists to assist in the field, as well as knowledge transfer to local, state, territorial, and international health departments.