Marijuana use among American young adults is rising, and perceptions of harm are declining. Individual states continue to enact more lenient marijuana use and possession laws. Marijuana use is associated with many serious negative outcomes. Thus, marijuana use among this age group has become a public health concern. According to Primary Socialization Theory, parents exert their influence on youth behavior through the parent-adolescent bond and through communication. Previous researchers have identified parent-offspring communication about alcohol and tobacco as a potentially important target of prevention efforts. Little research has yet explored marijuana communication and its potential influence on use-related outcomes. This study sought to model the influence of the parent-adolescent bond and parent-offspring communication about marijuana on marijuana use and problems related to use. In order to model this influence, the Communication about Marijuana (CAM) measure first was developed. In Study 1, an initial pool of items tapping marijuana communication was tested using a sample of 18-25 year old (M=20.22) undergraduate students (N=433). Confirmatory factor analyses were performed to test the fit of the data to the proposed model. In Study 2, a revised CAM measure was tested with a second sample of 18-25 year old (M=20.40) undergraduate students (N=432). The final measure included four content topic factors comprising 9 items, and 3 descriptive items tapping communication context. Structural equation models were specified to model the parent-adolescent bond and marijuana communication content on student self-reported past year marijuana use and marijuana use problems. Results suggested that the parent-adolescent bond was protective on marijuana use frequency, while models including only the manifest variable parental support better fit the data with regard to marijuana use problems. Communication content was somewhat differentially related to outcomes. Discussions encouraging abstinence, offering advice on peer pressure and monitoring use were related to more frequent use. Communication that conveyed disappointment about marijuana use and offered advice about peer pressure and choosing non-using friends was related to more marijuana use problems. Positive relations between communication and use outcomes were unexpected, but may reflect reactive parenting. Results and implications for future research are discussed in the context of the extant literature.