Male genital satisfaction is an important aspect of psychosocial and sexual health. The Index of Male Genital Image (IMGI) is a new scale that measures perceptions of male genitalia. We aim to characterize genital satisfaction using the IMGI and correlate dissatisfaction with sexual activity. We conducted a nationally representative survey of non-institutionalized adults aged 18-65 years residing in the U.S. In total, 4198 men completed the survey and 3996 (95.2 %) completed the IMGI. Men reported highest satisfaction with the shape of their glans (64 %), lowest satisfaction with the length of their flaccid penis size (27 %), and neutrality with the scent of their genitals (44 %). No demographic characteristics (age, race, sexual orientation, education, location, and income) were significantly associated with genital dissatisfaction. Men who were dissatisfied with their genitals were less likely to report being sexually active (73.5 %) than those who were satisfied (86.3 %). Penetrative vaginal sex (85.2 vs. 89.5 %) and receptive oral intercourse (61.0 vs. 66.2 %) were reported less by dissatisfied men. Overall, most U.S. men were satisfied with their genitals; however, a subset (14 %) report low genital satisfaction, which included men of all ages, races, and socioeconomic groups. Low genital satisfaction is associated with a decrease in sexual activity. These results provide clinicians and health educators a baseline of genital satisfaction to provide education and reassurance.