Dr. Nadal's research has focused primarily on multicultural issues in psychology, particularly on understanding impacts of microaggressions (subtle forms of discrimination) on the mental health of people of color, women, and lesbian/gay/bisexual/transgender/queer (LGBTQ) individuals. He is also considered one of the leading experts on Filipino American mental health and psychosocial issues affecting LGBTQ communities of color. He has written 8 books and over 100 publications, including Filipino American Psychology, the Sage Encyclopedia of Psychology and Gender, and Microaggressions and Traumatic Stress. He is the recipient of several awards, including the American Psychological Association Distinguished Contributions to the Public Interest and the Thought Leadership Award from the Robert Wood Johnson Foundation. He was the first openly gay president of the Asian American Psychological Association, the first person of color to serve as Executive Director of the Center for LGBTQ Studies at CUNY, and the founder of the LGBTQ Scholars of Color Network.