Young adulthood is a critical development period when mental health problems such as anxiety and depression become more prevalent. Likewise, there is evidence to suggest that depression and anxiety may lead to increased pornography usage. We examined the association of depression and anxiety symptoms with pornography viewing frequency among a prospective cohort of young adults (n = 1864) from California. Multinomial logistic regression models estimated the association of depression symptoms only, anxiety symptoms only, and comorbid depression and anxiety with pornography viewing frequency (never, < 3 times/month, one to several times/week, one to several times/day) at a 6-month follow-up. Models adjusted for gender, sexual orientation, sexual satisfaction, and adverse childhood experiences. Participants with comorbid depression and anxiety (vs. no depression or anxiety symptoms) had 2.72 (95% CI: 1.66–4.46) times the odds of frequent pornography viewing (one to several times/day) compared to never watching pornography. There was an association of depression symptoms only with frequent pornography viewing but it did not reach statistical significance (OR: 1.95, 95% CI: 0.78–4.89). Anxiety symptoms alone (vs. no depression and anxiety symptoms) were not associated with pornography viewing at any frequency in the full sample. However, in gender-stratified models, anxiety symptoms alone were associated with pornography viewing among women (OR: 1.44. 95% CI: 1.00–2.07), but not men (1.12, 95% CI: 0.65–1.96). Findings suggest comorbid depression and anxiety symptoms are associated with frequent pornography viewing among young adults, and anxiety symptoms alone are associated with pornography viewing among women, but not men.