Zajacova earned Ph.D. in Sociology and Demography from Princeton University in 2006. She joined Western Sociology in January 2017. Previously she was an Associate Professor of Sociology at the University of Wyoming, a National Institute on Aging Postdoctoral Fellow at the Population Studies Center at the University of Michigan, and an affiliate at the Population Research Center at the University of Texas at Austin.
Zajacova studies social determinants of population health across the life course. Her research aims to understand how and why educational attainment is related to health. She also explores how body weight and health are affecting one another, as well as how people evaluate and report their own health in surveys.