Several studies have suggested an association between serum copper, zinc, and selenium levels and psoriasis, but the results are disputable. Using data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES), this study examined the association of serum copper, zinc, selenium, and copper/zinc ratios with psoriasis in U.S. adults aged 20 years and older. Multifactorial logistic regression analysis was used to calculate the ratio (OR) and 95% confidence interval (CI) of serum copper, zinc, selenium, and copper/zinc ratios with psoriasis. A total of 3405 adults (1671 men and 1734 women) were enrolled. No significant correlations were found between psoriasis and serum copper, zinc, selenium, and copper/zinc ratios (highest versus lowest quartile) in multifactorial analyses with ORs of 0.65 (0.33, 1.29), 0.73 (0.39, 1.36), 0.82 (0.46, 1.47), and 1.05 (0.55, 2.00), respectively. The findings do not support a significant correlation between serum copper, zinc, and selenium levels and colorectal cancer risk in the general U.S. population.