Background: Evidence is emerging on how state-wide marijuana legalization and increased supply of DATA-2000 waivered providers may be associated with outcomes related to opioids. It is unknown whether such associations remain at the neighborhood level. Objectives: This study examined the associations of neighborhood availability of marijuana dispensaries and DATA-2000 waivered providers with opioid-related hospital stays. Methods: Discharge-level records of inpatient (N = 264,013) and observation stays (N = 12,621) were obtained from the Washington Comprehensive Hospital Abstract Reporting System from January through June 2016. Outcomes were indicators for inpatient stays related to opioid use disorder (OUD), inpatient stays related to opioid overdose, and observation stays related to OUD. Primary predictors were the density of marijuana dispensaries and DATA-2000 waivered providers at the zip code level. Multilevel logistic regressions with random intercepts were used to examine the cross-sectional associations, controlling for other patient and neighborhood characteristics. Results: Patients living in neighborhoods with one more recreational marijuana dispensaries per square mile were more likely (OR = 1.54, p = .017) to be diagnosed with OUD in inpatient stays. Living in neighborhoods with increased density of medical marijuana dispensaries or DATA-2000 waivered providers was not associated with being diagnosed with OUD or opioid overdose in inpatient or observation stays. Conclusions: Recreational and medical marijuana dispensaries were differentially associated with opioid-related hospital stays. Further investigations are warranted to explore the causal pathways of the findings.