The main objective of this study was to assess the health and economic impact of medical cannabis policy appropriate to the Thai context. It consists of three studies which are literature reviews to assess the positive and negative impacts of cannabis use in other countries, assessment of the medical cannabis demand and cost-benefit analysis of medical cannabis use. A review of international experiences of using medical and recreational cannabis can be concluded that elements of the cannabis legalization policy in each country affect accessibility to cannabis. The flexibility must be balanced between access to cannabis for therapeutic use among legally eligible patients, which is the benefit from the law; and the use in patients other than the permitted disease group, including leakage of drugs into recreational use which could have an impact on population health and public health where the cost of these impacts would affect the cost-benefit of medical policies. The medical cannabis demand was estimated using the burden of disease data or the number of patients in the disease groups that likely benefited from modern medical treatments using cannabis, including cancer patients with chemotherapy treatment, treatment of pediatric epilepsy, treatment of multiple sclerosis, and the treatment of neuropathic pain syndrome, as well as a group of promising therapeutic uses, such as, Parkinson’s disease, HIV patients, and those who seeking palliative treatment in the future. Estimated from 2013-2018 using mortality data to predict those seeking palliative care at the end of their life to 2030 shows that in 2018 the total number of a patient admitted from cancer was 212,256 cases, 10,128 from difficult and drug-resistant epilepsy in children under 14 years old, 281 from multiple sclerosis, 20,245 from neuropathy, 14,472 from Parkinson’s disease, 7,030 from HIV, and 53,924 cases from those needing palliative treatment. The result of the study to predict palliative care shows a trend of increasing demand for palliative care in the population group of 65 years and over, reflecting the growing demand for medical cannabis as the aging population grows. The cost-benefit analysis of medical cannabis policy, using decision tree and the Markov model with a societal perspective, by assigning 1 quality-adjusted life year (QALY) equal to GDP per capita, found that the use of cannabis according to medical indications was worthwhile for only one disease group, namely the treatment of chemotherapy-induced nausea and vomiting of cancer patients over a period of 5 years with a net result of 130 million baht. In summary, the benefits of medical cannabis use, including its use according to medical indications, use in diseases with no medical indication and for recreational use, indicate no economic value; by causing a negative impact on economics. This is due to the higher price of medical cannabis oil comparing to the standard regimens. While the use of cannabis in patients with no medical indications has a high cost of treating complications, as some patients will substitute cannabis for modern medicine. When patients stop using modern drugs, while the effects of cannabis are still lacking strong evidence, patient’s disease are more likely to occur as well as complications. There are also those who use cannabis for other unauthorized cases, such as for recreational use; which in this case will have negative impacts on both the cannabis users and other people in the society However, the implementation of the medical cannabis policy is also operating in the area of traditional Thai medicine, which has not been included in this study, as well as, the situation of using from illegal sources that the price may be higher than the standard price. Also, this study does not include community income if farmers are allowed to grow and sell cannabis, as well as export them. Therefore, in order to comprehensively assess the impact of the policy, the study should be expanded to cover the implementation of the policy in all sectors for further use in decision-making.