T This research concerns expert testimony in case number 1050/pid.sus/2022/pn dps, in which the expert stated that the defendant used narcotics for medical purposes and recommended that the defendant undergo rehabilitation. however, the judge determined that the defendant had abused narcotics. the research questions in this study are: (1) how is expert testimony regulated under the criminal procedure code (kuhap) for users of category i narcotics who have medical conditions? (2) does the expert testimony in decision number 1050/pid.sus/2022/pn dps have evidentiary value for users of category i narcotics who have medical conditions? this research employs a normative juridical method with a descriptive research approach. the data used are secondary data, collected through literature study, analyzed qualitatively, and conclusions are drawn using a deductive method. the results of the research indicate that the regulation of expert testimony under the criminal procedure code recognizes experts as a lawful means of evidence, including experts in the fields of addiction and narcotics rehabilitation. the expert testimony in decision number 1050/pid.sus/2022/pn dps was found to have influenced the judge in classifying the defendant as a person who abused narcotics for personal use and in imposing rehabilitation as a measure. however, its evidentiary value was limited because it was not supported by written medical evidence.