Paulina Kernberg's work included studies on the emotional effects of divorce, where she noted the trauma from divorce was second only to a parent's death in the perception of children involved. Following this work, she helped found a clinical program for children of divorced families at the New York-Presbyterian Hospital. She was the director of the Residency Program in Child and Adolescent Psychiatry at the New York Presbyterian Hospital, Payne Whitney Westchester-Weill Cornell Medical Center since 1978, until her death. She was a teacher at the Columbia University Center for Psychoanalytic Training and Research, where she was a supervising and training analyst in Psychoanalysis and Child Psychoanalysis. She authored over 100 articles and chapters in child psychiatry and psychoanalysis, and presented internationally and in multiple languages.
Kernberg was noted for her work evaluating Elián González, the 6-year-old Cuban boy at the center of an international custody battle in 2000 in what quickly became an inflammatory issue among Cuban-Americans and in the United States Congress. She described and proved that children show specific patterns of behavior in the playroom and repeat certain play themes according to their diagnosis. She also developed a questionnaire that the child psychiatrist uses during an assessment interview to measure the level of personality integration in adolescents, depending on their capacity to relate to peers and friends. She developed a standardized interview that is done to the mother and child when they are in front of a mirror, and also developed a similar instrument to assess the personality integration of adolescents. Kernberg was the first who described and studied with statistical analysis the early signs of personality disorders, which she said were already present and treatable in children and adolescents.
- Dynamite, a children's magazine to which Kernberg contributed an advice column