Internalized homophobia is a disorder consisting in the manifestation of anti-social prejudices directed at homosexual persons with the simultaneous presence of one’s own, unacceptable and suppressed homosexuality. Falloplethysmography (measurement of volumetric changes in an organ) is a study that was surprisingly used as early as 1996 to verify theories explaining homophobia, one’s own unacceptable homosexuality. Its results confirmed that the majority of homophobic people were in a state of internal conflict between feeling sexual attraction towards people of the same sex and displacing it. The work is theoretical, it is a review of the present research and shows a possible direction for the development of research on internalized homophobia with the use of phalloplethysmography. Internalized homophobia has a negative impact on the mental health (anxiety, depression, suicidal thoughts) of LGBT + people, it also implies a number of other social problems, e.g. risky sexual behavior, which increased risk of HIV infection. In the psychoanalytical sense, homophobia is a phenomenon of a fearful nature, namely the fear of being considered homosexual. Penile phalloplethysmography (PPG), mainly used in the field of research on sexual offenders, may also be used in the study of internalized homophobia. The literature on the subject emphasizes the legitimacy of taking into account individual psychological and social factors in research with the use of PPG.