Nancy Onisko, D.O.

  • Emergency Medicine


Nancy Onisko, D.O., FACEP, is an Assistant Professor in the Department of Emergency Medicine at UT Southwestern. She is also the co-director of the Perinatal Intervention Program at Parkland Hospital and Health System.  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 five 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, Ariz., in 2003.  She then completed her internship at Arrowhead Regional Medical Center in Colton, Calif., in 2004 and her residency in Emergency Medicine at Wayne State University and Detroit Receiving Hospital in Detroit, Mich., in 2007.  

Dr. Onisko is board certified in Emergency Medicine and spent five 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 second 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.

Education & Training
  • Medical School - Midwestern University Arizona College of Osteopathic Medicine (1999-2003)
  • Internship - Arrowhead Regional Medical Center (2003-2004), Rotating
  • Fellowship - UT Southwestern Medical Center (2013-2015), Toxicology
  • Residency - Wayne State University/Detroit Receiving Hospital (2004-2007), Emergency Medicine