Introduction. Cannabis usage has been a regular occurrence in Indonesia. According to the Indonesian national health survey in 2012, cannabis is the third most-used substance after nicotine and alcohol. A research done in a junior high school in Jakarta area found 70% of male students have tried cannabis. Cannabis is easier to get than other kinds of substance. Cannabis is closely related with Schizophrenia episodes in the future. Long term research done in 15 years from Andreasson said that Schizophrenia episodes on cannabis users within 15 years increased 2.4 times compared to non-cannabis users. Other impact of long term cannabis usage is neurocognitive disorder, since cannabis destroys the nerve's myelin. The neurocognitive disorders that can happen are attention disorder and memory disorder. Research on the impact of cannabis on cognitive functions has not been done in Indonesia. Therefore, in the interest of education regarding the negative impact of cannabis use we did the research on neurocognitive disorder on cannabis users. Methods. The research is done in Cipinang Jakarta prison. Sample taking was done using consecutive method with the number of sample 68 subjects. Subjects has inclusion criteria, i.e.: only use cannabis but have not use it in the last 72 hours. Neurocognitive examination was done using Ray Auditory Verbal Learning Test (RAVLT) questionnaire to check attention, verbal memory and working memory. Results. Subjects consists of 72% male and 28% female. Mostly aged between 24-29 years old (33.8%). Most are high school educated (60.3%). Eleven percent of them are housewives. Most of the subjects have been using cannabis for more than 2 years (69.1%). There is a correlation between education level and attention disorder. verbal memory and working memory disorders, where the higher the education level the lower the neurocognitive disorder (p = 0.002). Subjects with secondary high school education have more neurocognitive disorder (93%). The length of time of cannabis use also has correlation with neurocognitive disorder (p = 0.001). Subjects using cannabis more than 2 years have more neurocognitive disorder (72.3%). Conclusion. Neurocognitive disorder is a negative impact of using cannabis. Factors that affect the occurrence of neurocognitive disorder on cannabis users are the length of time of cannabis use and education level. The neurocognitive disorder that occurs are attention disorder, verbal and working memory disorders.