Objectives: Multiple-tobacco product (MTP) use is common among adolescent tobacco users. Low positive affect is a risk factor for e-cigarette use and combustible tobacco smoking. In this study, we examine the longitudinal relationship between positive affect and MTP use in a diverse cohort of adolescents in Texas. Methods: We analyzed 6 waves of biennial data (fall 2014-spring 2017) from the Texas Adolescent Tobacco and Marketing Surveillance (TATAMS) system. Participants were 3868 sixth-, eighth-, and tenth-grade students in urban Texas, at enrollment. Multinomial logistic regression models examined the longitudinal relationship between positive affect and categories of MTP use, controlling for sex, race/ethnicity, past 30-day alcohol use, cohort, survey wave, and peer tobacco use. Results: The sample was comprised of 4.6% single-product users, 1.7% dual-users, and 0.7% poly-users. Each unit decrease in positive affect was associated with increased risk for single- (RRR: 1.29; 95% CI: 1.16-1.44), dual- (RRR: 1.35; 95% CI: 1.11-1.64), and poly- (RRR: 1.98; 95% CI: 1.54-2.54) use, relative to non-use. Similarly, each unit decrease in positive affect was also associated with increased risk for poly-tobacco use relative to single- (RRR: 1.53; 95% CI: 1.19-1.97) and dual- (RRR: 1.47; 95% CI: 1.11-1.95) use. Positive affect did not differentiate between single- and dual-use. Conclusion: We observed a gradient relationship between low positive affect and greater number of tobacco products used. Findings reinforce the association between poor mental health and tobacco use during adolescence. Prevention efforts may need to incorporate methods of addressing low positive affect.