The present investigation examined two theoretically relevant aspects of marijuana motives using the Marijuana Motives Measure (MMM) [Simons, J., Correia, C. J., Carey, K. B., & Borsari, B. E. (1998). Validating a five-factor marijuana motives measure: Relations with use, problems, and alcohol motives. Journal of Counseling Psychology 45, 265–273] among 141 (78 female) young adults (Mage = 20.17, S.D. = 3.34). The first objective was to evaluate the incremental validity of marijuana motives in relation to frequency of past 30-day use after controlling for the theoretically relevant factors of the number of years using marijuana (lifetime), current levels of alcohol, as well as tobacco smoking use. As expected, coping, enhancement, social, and expansion motives each were uniquely and significantly associated with past 30-day marijuana use over and above the covariates; conformity motives were not a significant predictor. A second aim was to explore whether coping, but no other marijuana motive, was related to the emotional vulnerability individual difference factor of anxiety sensitivity (fear of anxiety). As hypothesized, after controlling for number of years using marijuana (lifetime), past 30-day marijuana use, current levels of alcohol consumption, and cigarettes smoked per day, anxiety sensitivity was incrementally and uniquely related to coping motives for marijuana use, but not other motives. These results are discussed in relation to the clinical implications of better understanding the role of motivation for marijuana use among emotionally vulnerable young adults.