Dr. Padilla's research follows three major strands: (1) resilient students who achieve high levels of academic performance despite coming from home and community backgrounds that pose multiple challenges to educational excellence, including adaptation to U.S. culture and English by immigrant adolescents; (2) acculturation and acculturation stressors that impact the physical and psychological well-being of newcomer youth and adults as well as the acquisition of bicultural strategies for functioning in their home culture and in mainstream American culture; and (3) studies involving second language learning and teaching, and strategies for achieving bilingual proficiency especially among heritage speakers of numerous European and Asian languages. He has published widely in his areas of research expertise.

Dr. Padilla is also interested in quantitative research in multicultural contexts. He serves as the principal investigator of the California World Language Project (CWLP), a program that assists California teachers in world language instruction. A final interest includes the history of ethnic minority scholars in psychology.