Nancy Onisko, D.O., FACEP is an Assistant Professor in the Department of Emergency Medicine at the University of Texas Southwestern Medical Center. She is also the co-director of the Perinatal Intervention Program at Parkland Hospital and Health System in Dallas, TX.  Her areas of interest include addiction medicine, general toxicology, toxinology (the study of venomous animals and poisonous plants), new drugs of abuse, international toxicology and the advancement of addiction medicine and medical toxicology as a specialty. 


Dr. Onisko earned a Bachelor of Science degree in Psychology from Michigan State University.  After college, she spent 5 years working as a Clinical Research Associate at the University of California at San Diego before pursuing her dream of becoming a physician.  She graduated from Midwestern University, Arizona College of Osteopathic Medicine in Phoenix, Arizona in 2003.  She then completed her internship at Arrowhead Regional Medical Center in Colton, California in 2004 and her residency in Emergency Medicine at Wayne State University and Detroit Receiving Hospital in Detroit, Michigan in 2007.  


Dr. Onisko is board certified in Emergency Medicine and spent 5 years practicing community-based emergency medicine in California before returning to academia to pursue a fellowship in toxicology. She enjoyed the cerebral atmosphere of academia so much that she then completed a 2nd fellowship in Global Health and Disaster Medicine and stayed on as an attending physician and Clinical Professor of Emergency Medicine at UTSW. Her passions outside of medicine include international travel, tennis, music, photography, social justice issues and animal rescue.



Medical School
Midwestern University (2003)
Arrowhead Regional Medical Center (2004), Rotating
Wayne State University/Detroit Receiving Hospital (2007), Emergency Medicine
UT Southwestern Medical Center (2015), Toxicology